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Glossary of Foundry Terms

AAR

Association of American Railroads

Abrasion

The displacement and/or detachment of metallic particles from a surface as a consequence of being exposed to flowing solids, fluids or gases.

Abrasion Resistance

Degree of resistance of a material to abrasion or wear.

Abrasive Wear

The displacement and / or detachment of metallic particles from a surface as a consequence of being exposed to flowing fluids or gases.

Abrasives

Materials for grinding, polishing, blasting, either in loose form or bonded to form wheels, bricks, or files, or applied to paper and cloth by glue or resin. Natural abrasives include emery, corundum, garnet, sand, flint, etc. Metallic shot and grit are also used as abrasives in cleaning castings.

Ac1

The temperature at which austenite begins to form on heating.

Ac3

In hypoeutectoid steel, the temperature at which transformation of ferrite into austenite is completed upon heating.

Accelerator

A substance that hastens a reaction usually acting as a catalyst; as used in sand additive resins.

Accm

In hypereutectoid steel, the temperature at which cementite goes into complete solution with austenite.

Acid

1) A solution or liquid with a pH less than 7, 2) term applied to slags, refractors, and minerals containing a high percentage of silica.

Acid Brittleness (Picking Brittleness)

Lack of ductility, induced in steel when it is pickled in dilute acid to remove scale - commonly attributed to the absorption of hydrogen.

Acid Embrittlement

Embrittlement during pickling due to absorption of hydrogen.

Acid Process

A steel making method using an acid refractory-lined (usually silica) furnace. Neither sulfur or phosphorus is removed.

Adapti Investment Casting Process

A lost wax process employing one of three methods; centrifugal, vacuum or gravity-pouring casting.

Adeline Steelmaking Process

Method of producing a precision casting of steel or steel alloys using aluminolthermic process and lost wax, followed by centrifugal action.

Addition Agent

1) Any material added to a charge of molten metal in bath or ladle to bring alloy to specifications, 2) reagent added to plating bath.

Aecm, Ae1, and Ae3

Equilibrium transformation temperatures in steel.

Aeration

Making contact between air and a liquid by spraying liquid into the air or by agitating the liquid to promote absorption of air. Also act of fluffing molding sand.

AFS

American Foundry Society

AFS Tests

A number of standard tests determined by American Foundrymen's Society to evaluate molding and core sands.

Age Hardening

Hardening by aging, usually after rapid cooling or cold working.
See also Precipitation Hardening

Aging

A change in properties of metals and alloys which occurs slowly at room temperature and will proceed rapidly at higher temperatures. The change in properties is often, but not always, due to a phase change (precipitation), but never involves a change in chemical composition of the metal or alloy.
See also Age Hardening

Air Furnace

Reverbatory-type furnace in which metal is melted by heat from fuel burning at one end of the hearth, passing over the bath toward the stack at the other end. Heat also is reflected from the roof and side walls.

Air-Hardening Steel

A steel containing sufficient alloy to fully harden during cooling in air. Typically this term is restricted to steels being able to harden in sections of about 2 in. (51 mm) or more.

Air Quenching

Accelerated cooling of alloy in an air stream from temperatures above the Ac3 temperature.

Air Scale

Scale left on ferrous metal in processing, usually from heating in presence of air.

Airblasting

A cleaning operation, as cleaning sand from molds.

Alkaline Derusting

An electrical process for derusting steel, cast iron and other ferrous alloys without using heat.

Allowance (Tolerance)

In a foundry, the clearance specified; difference in limiting sizes, as minimum clearance or maximum interference between mating parts, as computed arithmetically.

Alloy

A substance having metallic properties and composed of two or more chemical elements of which at least one is metal. Usually possesses qualities different from those of the components.

Alloy Steel

Steel containing significant quantities of alloying elements other than carbon and the commonly accepted amounts of manganese, silicon, sulfur, and phosphorus.

Alpha - ferrite

Body-centered cubic type of pure iron stable below 1670F (910C).

Alpha Martensite

A form or stage of martensite of somewhat arbitrary distinction, probably representing the least developed and most distorted stage in the transformation of austenite to martensite at ordinary temperatures.

Alpha Process

A shell molding and core-making method in which a thin resin-bonded shell is baked with a less expensive, highly permeable material.

Alternating Stress

Stress produced in a material by forces acting alternating in opposite directions.

Ambient Air

The surrounding air.

Ambient Temperature

Temperature of the surrounding air.

Ames Portable Hardness Tester

The Rockwell penetration method of testing hardness of metals can be made with this tester by applying pressure to the penetrator by screw action.

Analysis Line

In spectrographic analysis, the particular spectral line used in determining the concentration of an element.

Angle Testing

A method of ultrasonic testing using shear waves introduced from the surface of the material at approximately 45 degrees.

Anisotropy

The characteristic of exhibiting different property values in different directions with respect to a fixed reference system in the material.

Annealing

Heating to and holding at a suitable temperature, followed by cooling at a suitable rate to lower the hardness or alter other mechanical or physical properties.

Anticarburizing Compounds

Compounds applied to metallic surfaces to prevent surface carbonization.

AOD

See Argon Oxygen Decarburization

APFIM - Atomic Probe Field Ion Microscopy

An analytical technique in which atoms are ionized by an electric field near a sharp specimen tip. The field then forces the ions to a fluorescent screen which shows an enlarged image of the tip and individual atoms are made visible.

Apparent Contraction

The net contraction of a casting dimension due to true metal contraction, mold wall movement and restraint during solidification and cooling.

Arc Cutting

Using an electric arc to cut metal.

Arcair Torch

An electric arc torch with air ducts running parallel to the electrode, used to remove metal and surface defects from ferrous castings.

ARD Process

A refinement of the precision casting process, using plastic patterns produced in automatic injection machines.

Argon Oxygen Decarburization (AOD)

A secondary refining process in which argon, oxygen and nitrogen are injected into a molten bath of steel. The AOD process improves metal cleanliness and thus gives superior mechanical properties.

Arnold's Fatigue Test

(after John Arnold, Brit. Met.), a test for fractures using 850 cyclic stress reverses per min., recording the number of cycles required to produce fracture.

Artifical Aging

An aging treatment above room temperature.
See Agingand Age Hardening

As Cast (as-cast, u.m.)

Referring to metal which has not received finishing (beyond gate removal or sandblasting) or treatment of any kind including heat treatment after casting. Similarly, as drawn, as forged and as rolled. (See Finishing)

ASM

See American Society for Metalsfor association address information.

ASNT

See American Society for Nondestructive Testingfor association address information.

ASTM

See American Society for Testing and Materialsfor association address information.

Atmosphere, Furnace

Gases with which metal is in contact during melting or heat treating.

Atmosphere, Neutral

Furnace atmosphere which is neither oxidizing nor reducing can be made up of an inert gas e.g. argon, or the products of combustion.

Atmosphere, Oxidizing

Furnace atmosphere which gives off oxygen under certain conditions or where there is an excess of oxygen in the product of combustion, or the products of combustion are oxidizing to the metal being heated.

Atmosphere, Reducing

Furnace atmosphere which absorbs oxygen under suitable conditions or in which there is insufficient air to completely burn the fuel, or the product of combustion is reducing to the metal being heated.

Austenite

The face-centered-cubic phase of iron and steel, also referred to as gamma iron. In steel, a solid solution in which gamma iron is the solvent.

Backing Board (Backing Plate)

A second bottom board on which molds are opened.

Bainite

In steel, an acicular aggregate of ferrite and carbide, resulting from an isothermal transformation of austenite at a temperature below the pearlitic range and above Ms.

Bake

Heat in an oven to a low controlled temperature to remove gases or to harden a binder.

Baked Core

A core which has been heated through sufficient time and temperature to produce the desired physical properties attainable from its oxidizing or thermal-setting binders.

Baked Strength

Compressive, shear, tensile or transverse strength of a mold sand mixture when baked at a temperature above 231°F (111°C) and then cooled to room temperature.

Ball Burnishing

A method of obtaining a high luster on small parts by rotating them in a wooden-lined barrel with water, burnishing soap, and stainless steel shot.

Band, Inside

A loose steel frame placed inside a removable flask to reinforce the sand at the parting line after the flask has been removed.

Bark

The decarburized layer just beneath the scale resulting from heating steel in an oxidizing atmosphere.

Bars (Cleats)

Ribs of metal or wood placed across the flask to help support the sand in the cope.

Base Plate

A plate to which the pattern assemblies are attached and to which a flask is subsequently attached to form the mold container.

Batch

Amount or quantity of core or mold sand or other material prepared at one time.

Batch Oven

Oven use to bake a number of cores at one time.

Bath

Molten metal on the hearth of a furnace, in a crucible, or in a ladle.

Batten

A wooden bar or strip fastened to bottom or follow board for rigidity or to prevent distortion during ramming of the mold.

Bead

1)Half-round cavity in a mold, or half-round projection or molding on a casting, 2) a single deposit of weld metal produced by fusion.

Beam and Sling

Tackle used in conjunction with a crane for turning over the cope or drag of a mold prior to assembly.

Bedding

Sinking a pattern down into the sand to the desired position and ramming the sand around it.

Bedding a Core

Resting an irregularly shaped core on a bed of sand for drying.

Bed-In

Method whereby drag may be rammed in the pit or flask without necessity of rolling over. Process used in production of heavy castings.

Bench-Blower

A small core-blowing machine, utilizing a removable sand magazine and blow heat.

Bench Rammer

A short rammer used by bench molders.

Bending Strength

Upper limit of normal stress of a beam at which fracture or excessive plastic deformation occurs.

Bentonite

A colloidal clay derived from volcanic ash and employed as a binder in connection with synthetic sands, or added to ordinary natural (clay-bonded) sands where extra strength is required.

BHN

Brinell Hardness Number

Bimetal

Casting, usually centrifugal, made of two different metals, fused together.

Black Lead

A natural form of graphite used for sleeking green sand molds, or applied in a water suspension to skin dried molds.

Blackening Scab

A form of casting defect related to an improper coating rather than to the sand.

Blacking Carbon

Carbonaceous materials such as plumbago, graphite or powdered coke usually mixed with a binder and frequently carried in suspension in water or other liquid; used as thin facing applied to surfaces of molds or cores to improved casting finish.

Blacking Hole

Irregular-shaped surface cavities in a casting containing carbonaceous matter. Caused by spilling off of the blacking from the mold surface.

Blacking Scab

A casting defect formed by blacking flaking off due to sand expansion and being retained in or on the surface of the metal.

Blasting (Blast Cleaning)

A process for cleaning or finishing metal objects by use of an air blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Small, irregular particles of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting.

Bleeder

A defect wherein a casting lacks completeness due to molten metal draining or leaking out of some part of the mold cavity after pouring has stopped.

Blended Molding Sands

Naturally bonded molding sands which have been mixed or modified by the supplier to produce desirable properties.

Blister

A shallow blow with a thin film of the metal over it appearing on the surface of a casting.

Blocking

Adding ferrosilicon or other deoxidizing agent to a refined heat to stop all oxidizing reactions.

Blow Holes

1) Holes in the head plate or blow plate of a core-blowing machine through which sand is blown from the reservoir into the core box. 2) Irregular shaped cavities with smooth walls produced in a casting when gas is entrapped during mold filling. The gas sources may be air, binder decomposition products or gases dissolved in the molten steel.

Blow Plate

The plate containing the core sand entrance holes or blow holes used in open-face core boxes.

Blower, Core or Mold

A device using air pressure to fill a core box or flask with sand.

Blowing-Off a Mold

Cleaning a mold cavity with a stream of compressed air.

Blowpipe

A small pipe or tube through which the breath is blown in removing loose sand from small mold cavities.

Blows

See Blowholes

Bluing

Formation of a thin film of oxide on polished steel to improve its appearance and protect its surface.

Bob

A riser or feeder, usually blind, to provide molten metal to the casting during solidification, thereby preventing shrinkage cavities.

Body Core

The main core.

Boil

Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated.

Bond

1) Bonding substance or bonding agents - any material other than water, which, when added to foundry sands, imparts bond strength, 2) the overlapping of brick so as to give both longitudinal and transverse strength.

Bond Strength

Property of a foundry sand to offer resistance to deformation.

Bonding Clay (Bonderise)

Any clay suitable for use as a bonding material.

Boring

A machining method using single point tools on internal surfaces of revolution.

Boss (Pad)

A projection of circular cross-section on a casting. Usually intended for drilling and tapping for attaching parts.

Bottom Pour Ladle

See Ladle, Bottom Pour

Bottom Running or Pouring

Filling of the mold cavity from the bottom by means of gates from the runner.

Bracket

Strengthening strip, rib, or projection on a casting; usually used to prevent hot tearing.
Also see cracking Strip

Breaker Ring

An intentionally weak ring within mass of a ring shell mold to be broken by force of casting shrinkage. Prevents hot tear stress.

Breakoff Notch

A thinner section of a gate or riser to facilitate and ensure clean breaking-off during the cleaning process of casting.

Bright Annealing

A process carried out usually in a controlled furnace atmosphere, so surface does not oxidize, remaining bright.

Brinell Hardness

The value of hardness of a metal on an arbitrary scale representing kg/mm2, determined by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN

Brittle Fracture

Fracture with little or no plastic deformation.

Brettleness

A tendency to fracture without appreciable deformation.

Broaching

Smoothing machined holes or outside surfaces of castings by drawing pushing on or more broaches (special cutting tools) through the roughed out hole.

Buckle

1) Bulging of a large flat face of a casting; in investment casting, caused by dip coat peeling from the pattern, 2) an indentation in a casting, resulting from expansion of the sand, may be termed the start of an expansion defect.

Builtup Plate

A pattern plate of suitable material, with the cope pattern mounted on or attached to one side; the drag pattern may be attached to the other side or to a separate mounting.
See Matchplate

Bulk Density

The ratio of the weight of a material to its over-all volume (including any inherent porosity).

Bull Ladle

See Ladle, Bull

Bumper

A machine for ramming sand in a flask by repeated jarring or jolting.

Burn

1) Process of cutting metal by a stream of fuel and oxygen, 2) to permanently damage a metal or alloy by heating to cause either incipient melting or intergranular oxidation.

Burned Sand

Sand in which the binder or bond has been removed or impaired by contact with molten metal.

Burned-On-Sand

A misnomer usually indicating metal penetration into sand resulting in a mixture of sand and metal adhering to the surface of a casting.

Burning In

See Penetration, Metal

Burnishing

Developing a smooth finish on a metal by tumbling or rubbing with a polished hand tool.

Burnthrough

In shell molding, resin burned out too soon.

Butt Off

Operation performed at times to supplement ramming by jolting, either hand or air rammer.

C

Degrees Centigrade or Celsius.

C or Croning Process

See Shell Molding.

CAD

Computer-Aided Design.

CAE

Computer Aided Engineering.

Calcium Silicide

An alloy of Calcium, silicon, and iron containing 28-35% Ca, 60-65% Si, and 6% Fe, max., used as a deoxidizer and degasser for steel and cast-iron; sometimes called calcium silicide.

Calcium Silicon

An alloy of calcium, silicon, and iron containing 28-35% Ca, 60-65% Si, and 6% Fe, max., used as a deoxidizer and degasser for steel and cast-iron; sometimes called calcium silicide.

Calcium Wired Injection

Wire feeding of steel clad calcium wire into molten bath to provide favorable kinetics for inclusion modification.

CAM

Computer-Aided Manufacturing.

Camber

Deviation from edge straightness usually referring to the greatest deviation of side edge from a straight line.

Carbide

A compound of carbon with one or more metallic elements.

Carbon

Element occurring as diamond and as graphite. Carbon reduces many metals from their oxides when heated with the latter, and small amounts of it greatly affect the properties of iron. Though classed as a nonmetallic, metallurgically, like boron, it is treated as a metal.

Carbon Boil

See Boil.

Carbon, Combined

The carbon in iron or steel which is combined with other elements and therefore is not in the free state as graphite or as temper carbon.

Carbon Dioxide Process (Silicate Process, Schmidt Philip Process

A process for hardening molds or cores in which carbon dioxide gas is blown through dry clay-free silica sand to precipitate silica in the form of a gel from the sodium silicate binder.

Carbon Sand

A molding aggregate consisting principally of carbon (graphite) granules.

Carbonitriding (Nicarbing)

A process in which a ferrous alloy is case hardened by first being heated in a gaseous atmosphere of such composition that the alloy absorbs carbon and nitrogen simultaneously, and then being cooled at a rate that will produce desired properties.

Carburizing

A form of case hardening that produces a carbon gradient inward from the surface, enabling the surface layer to be hardened by either quenching directly from the carbonizing temperature or by cooling to room temperature, then reaustenitizing and quenching.

Carpel Tunnel Syndrome

Pressure on the median nerve at the point at which it passes through the carpel tunnel of the wrist. Causes soreness and tenderness of the muscles of the thumb.
(See CTD).

Case

The surface layer of an iron-base alloy which has been suitably altered in composition and can be made substantially harder than the interior or core by heat treatment.

Case Hardening

A process of hardening a ferrous alloy so that the surface layer or case is made substantially harder than the interior or core. Typically case hardening process are carburizing, carbonitriding, and nitriding.

Cast-Weld

Welding one casting to another to form a complete unit.
See Fabrication

Casting Drawing

An engineering drawing which depicts the shape and size of a part to be cast.

Casting Layout

A check of dimensions against applicable drawings and specifications.

Cavitation

The formation and collapse of cavities or bubbles within a liquid.

Cementite

A compound of iron and carbon commonly known as iron carbide and having the approximate chemical structure, Fe3C. Cementite is characterized by an orthorhombic crystal structure.

Centrifugal Casting

Casting made in molds which are rotating so as to produce a centrifugal force in the molten metal.

CERCLA

Comprehensive Environmental Response, Compensation and Liability Act. 1980.

Ceroxide

See Inclusions

Chaplet

Metal support that holds a core in place within a mold; molten metal solidifies around the chaplet and fuses it into the finished casting.

Charpy Impact Test

A pendulum-type single-blow impact test in which the specimen, usually notched, is supported at both ends as a simple beam and broken by a falling pendulum. The energy absorbed in fracture, as impact strength or notch toughness.

Cheek

The intermediate section of a flask that is used between the cope and the drag when molding a shape requires more than one parting plane.

Chicken Wire Cracks

See Craze Cracking

Chill (External)

Metal, graphite or carbon blocks that are incorporated into the mold or core to locally increase the rate of heat removal during solidification and reduce shrinkage defects.

Chill (Internal)

A metallic device / insert in molds or cores at the surface of a casting or within the mold to increase the rate of heat removal, include directional solidification and reduce shrinkage defects. The internal chill may then become a part of the casting.

Chromel

A 90Ni - 10Cr alloy used in thermocouples.

Chromite

FeCr2O4. Specialty sand used in molding, has a similar effect to chills.

CLAS

A casting process in which metal fills the mold through the drag by application of a vacuum.

Cleaning

The removal of gates, runners and risers from the rough casting. This term also involves any hand finishing such as grinding or blasting.

CMF

Cast Metals Federation - Defunct

CMM

Coordinate Measuring Machine.

CNC

Computer Numerical Controlled Machine Tools.

Coalescence

1) the growth of particles of a dispersed phase by solution and reprecipitation, 2) the growth of grains by absorption of adjacent undistorted grains.

Cobalt

Blue-white metal, melting at 2715°F (1492°C), used in very hard alloy such as stellite, and a binder in carbide cutting tools.

Cobalt-60

A radioactive isotope used in medical and industrial radiography.

Cocoon Process

A method of protecting metal parts by spraying on a cover of plastic filaments.

Code

In EDP, a system of symbols and their use in representing rules for handling the flow or processing of information.

Code Holes

The information holes in perforated tape, as opposed to feed or sprocket holes.

Coefficient of Expansion

Unit increase in size resulting from a unit increase in temperature; measured in inches per inch per degree Fahrenheit (in/in/1/2°F) or in millimeter per millimeter per degree Celsius (mm/mm/1/2°C).

Coercive Force

The magnetizing force that must be applied in the direction opposite to that of the previous magnetizing force in order to remove residual magnetism; thus, an indicator of the strength of magnetically hard materials.

Cohesion

The force by which like particles are held together. It varies with different metals and depends upon molecular arrangement due to heat treatment.

Coining

1) A process of straightening and sizing casting by die pressing, 2) a process for shaping metal.

Coke

A porous, bray infusible product resulting from the dry distillation of bituminous coal, petroleum or coal tar pitch, which drives off most of the volatile matter. Used as a fuel in cupola melting.

Coke Bed

First layer of coke placed in the cupola. Also the coke as the foundation in constructing a large mold in a flask or pit.

Coke, Beehive

Coke produced from a bituminous coal by the beehive process where heat for the coking process comes from a partial combustion of the coke. Generally characterized by an elongate stringy structure.

Coke Breeze

Fines from coke screening, used in blacking mixes after grinding; also briquetted for cupola use.

Coke, By-Product

Coke produced from bituminous coal in airtight code ovens where heat for coking process is externally applied. Generally more uniform in size than beehive coke, and usually ball or cube shape.

Coke Furnace

Type of pot or crucible furnace using coke as the fuel.

Coke, Petroleum

Residue left from the distillation of petroleum crude, used as a carbon raiser.

Coke Porosity

The percentage volume of cell space in coke.

Cold-Box Process

1) Any core binder process that uses a gas or vaporized catalyst to cure a coated sand while it is in contact with the core box at room temperature.

Cold Chamber Machine

A diecasting machine where the metal chamber and plunger are not immersed in hot metal.

Cold Chamber, Club Sandwich, Two-Faced, Three-Piece Die

A diecasting die in which two different pieces are cast in two widely separated cavities.

Cold Cracking

Cracks in cold or nearly cold metal due to excessive internal stress caused by contraction. Often brought about when the mold is to hard or casting is of unsuitable design.

Cold Lap

Wrinkled markings on the surface of an ingot or casting from incipient freezing of the surface.

Cold Setting Process

An of several systems for bonding mold or core aggregates by means of organic binders, relying upon the use of catalysts rather than heat for polymerization (setting).

Cold Setting Binders

Term used to describe any binder that will harden the core sufficiently at room temperature so core can be removed from its box without distortion; commonly used in reference to oil-oxygen type binders.

Cold Short

A characteristic of metals that are brittle at ordinary or low temperatures.

Cold Shot

Small globule of metal embedded in but not entirely fused with the casting.

Cold Shut

Casting defect caused by imperfect fusing or discontinuity of molten metal coming together from opposite directions in a mold, or due to folding of the surface. It may have the appearance of a crack or seam with smooth, rounded edges. Also see Cold Lap

Cold Work

Plastic deformation of a metal at room temperature. Substantial increases in strength and hardness may occur.

Collapsibity

The requirement that a sand mixture break down under the pressure and temperatures developed during casting, in order to avoid hot tears or facilitate the separation of the sand and the casting.

Collapsible Sprue

A sprue pattern of flexible material, or of spring-tube design, used in squeeze-molding of plated patterns, and incorporating a pouring cup.

Collate

1) to merge items from two or more similarly sequenced files into one sequenced file, 2) to compare one thing critically with another of the same kind.

Collimator

A device for confining the elements of a beam of radiation within an assigned solid angle.

Colloids, Colloidal Material

Finely divided material less than 0.5 micron (0.00002 in.) in size, such as albumin, glue, starch, gelatin, and bentonite.

Colloidal Clay

Finely divided clay of montmorillonite, kaolinite, or illite class; prepared for foundry purposes as in sand bonding.

Color Etching

A micro-etch resulting from the formation of a thin film of a definite compound of the metal

Coloimetric Analysis

Determining the amount of an element in a solution by measuring the intrinsic color.

Columnar Structure

A coarse structure of parallel columns of grains, which is caused by highly directional solidification.

Combination Die (Multiple-Cavity Die)

In die casting, a die with two or more different cavities for different castings.

Combined Carbon

Carbon in iron and steel which is combined chemically with other elements; not in the free state as graphitic or temper carbon.

Combined Water

That water in mineral matter which is chemically combined and driven off only at temperatures above 231°F (111°C).

Combustion

Chemical change as a result of the combination of the combustible constituents of the fuel with oxygen, producing heat.

Combustion Chamber

Space in furnace where combustion of gaseous products from fuel takes place.

Combustion Efficiency

The amount of heat usefully available divided by the maximum amount which can be liberated by combustion; usually expressed in percentage.

Comfort Zone (Average)

The range of effective temperature over which the majority (50% or more) of adults feel comfortable.

Composite Construction

Welding a steel casting to a rolled or forged steel object or to another casting.
See Cast-Weld

Compression Test

Imposing a dead load on a small cylindrical test piece to determine compressive strength, expressed in pounds per sq. in.

Comressive Strength (Yield)

The maximum stress in compression that can be withstood without plastic deformation or failure.

Compressor

Device for providing gas under pressure. Usually connotes high pressures and not so high volume.

Condensing Rings

A special form of chill used for cast iron to produce a dense but graphite structure.

Conduction

The transmission of heat, sound, etc. by the transferring of energy from one particle to another.

Conductivity (Thermal)

The quantity of heat that flows through a material measured in heat units per unit time per unit of cross-sectioned area per unit of length, (electrical) the quantity of electricity that is transferred through a material of know cross-section and length.

Connor Gate (Runner) (Lip Feeder)

A runner in which the feed block overlaps the casting by 1/16 in. (1.6 mm).

Constant Intensity Pyrometer

Use of a comparison lamp filament's glow to estimate metal temperature.

Constantan

An alloy of nickel and copper use in thermocouples.

Constituent

A micrographically distinguishable part of an alloy or mixture.

Consumer's Risk

The risk the consumer runs of accepting lots of quality p2.

Conact Cement

Patternmaking bonding technique, in which liquid bonding agent is painted on both surfaces to be joined and allowed to dry. These dry surfaces placed in contact adhere firmly.

Contact Printing (Ink Print)

A method of recording details of a macroetched structure.
See Sulfur Prints.

Contamination

1) Radioactive deposition of radioactive material in any place where it is not desired, and particularly in any place where its presence may be harmful. The harm may be in vitiating the validity of an experiment or a procedure, or in actually being a source of danger to personnel, 2) presence of small percentages of deleterious elements in an alloy adversely affecting the alloy's mechanical properties and/or casting soundness.

Continuous Annealing Furnace

Furnace in which castings are annealed or heat treated by passing through different zones at constant temperatures.

Continuous Desulfurization

A process of removing sulfur from molten ferrous alloys on a continuous basis.

Continuous Mixer

Used to continuously mix chemically bonded sand.

Continuous Phase

The phase that forms the matrix or background in which the other phases are present as isolated units.

Continous Tapping

A furnace or holding ladle that is made of discharge molten metal continuously during normal operation.

Contraction

The volume change occurring in metals (except antimony and bismuth) and alloys on solidification and cooling to room temperature.

Contraction Cracks

Cracks formed by restriction of the metal while contracting in the mold; may occur just after solidification (called a hot tear) or a short time after the casting has been removed from the mold.
See Hot Tears

Contraction Rule

See Shrinkage, Patternmaker's

Contolled Area

A defined area in which the occupational exposure of personnel to radiation or to radioactive material is under the supervision of an individual in charge of radiation protection.

Controlled Atmosphere

Any gas or mixture of gases that prevents or retards oxidation and decarburization.

Controlled Cooling

See Cooling, Controlled

Convection

The motion resulting in a fluid from the differences in density. In heat transmission, this meaning has been extended to include both forced and natural motion or circulation.

Converter

A furnace in which a gas, usually air, is blown through the molten bath or crude metal for the purpose of oxidizing impurities.

Conveyor

A mechanical apparatus for carrying or transporting materials from place to place. Types include apron, belt, chain, gravity, roller, monorail, overhead, pneumatic, vibrating, etc.

Conveyor Belt

A continuously moving belt used in an automated or semiautomatic foundry to move materials from one station to another.

Conveyor, Pallet

A materials-handling device that holds one or more molds and transports them from the molding station through pouring to shakeout.

Conveyor, Pneumatic Tube

An air-tube means of moving materials from on place to another, primarily orders, light metal samples, and sand and other finely divided materials, as bentonite.

Conveyor, Roller

A line of conveyance in an automated or semiautomated foundry which employs a series of steel roller for moving objects.

Conveyor Screw

Rotary worm-type blade used to move materials in automated core and mold making and other continuous sand-mixing operations.

Conveyor, Slat

A materials-handling device built on a continuous belt of metal slats that moves granular materials and castings throughout a foundry.

Convery, Vibratory

A materials-handling device used usually with shakeout operations, to help clean sand from the castings as they are moved from one place to another in the foundry and as a feeding device to regulate materials flow. Operations with vibrational energy.

Cooler

The largest of three water coolers surrounding the cinder notch of a blast furnace.

Cooling, Controlled

A process of cooling from an elevated temperature in a predetermined manner used to produce a desired microstructure to avoid hardening, cracking or internal damage.

Cooling Curve

A curve showing the relationship between time and temperature during the solidification and cooling of a metal sample. Since most phase changes involve evolution or absorption of heat, there may be abrupt changes in the slope of the curve.

Cooling Fin

See Cracking Strip

Cooling Stress

Stresses developed by uneven contraction or external constraint of metal during cooling.

Cope

Upper or topmost section of a flask, mold or pattern.

Cope, False

Temporary cope used only in forming the parting and therefore not a part of the finished mold

Coping Out

The extension of sand of the cope downward into the drag, where it takes an impression of a pattern.

Copper

For foundry applications, copper is meant to include all alloys containing 98% or more copper. Used for conductivity castings. Melting point 1083°C (1981.4°F).

Copper, Electrolytic

Copper produced by the electrolysis method.

Corbel

One or more projecting courses of brick each projecting beyond the course below.

Core

A performed sand aggregate inserted in a mold to shape the interior or that part of a casting which cannot be shaped by the pattern.

Core Arbor

An iron framework embedded in a large core to stiffen it and for convenience in handling.

Core Assembly

Putting together a complex core made of a number of sections.

Core-Baking Dielectric

Heating cores to baking temperatures by means of high-frequency dielectric equipment; particularly adapted to thermo-setting resin core binders.

Core Barrel

Pipe-shaped device upon which a cylindrical core is formed.

Core Binder

Any material used to hold the grains of core sand together.

Core Blow

A gas pocket in a casting adjacent to a core cavity caused by entrapping gases from the core.

Core Box, Combination

Core box and core dryers from the same pattern. One half is used as a half core box and a core drier.

Core Branch

Part of a core assembly.

Core Breaker

A machine for crushing cores or for removing cores from castings.

Core Cavity

The interior form of a core box that gives shape to the core. Also, the cavity produced in a casting by use of a core.

Core Collapsibility

The rate of disintegration of the core at elevated temperature.

Core Compound

A commercial mixture used as a binder in core sand.

Core Crab

An iron framework embedded in a large core to stiffen it and for convenience in handling.

Core Density

1) Permeability of core or 2) weight per unit volume.

Core Driers

Supports used to hold cares in shape while being baked; constructed from metals or sand for conventional baking, or from plastic material for use with dielectric core-baking equipment.

Core Extruder

A special shell-core-making machine that produces a continuous length of cores, usually of cylindrical cross-section.

Core Filler

Material used in place of sand in the interiors of large cores - coke, cinder, sawdust, etc., usually added to aid collapsibility.

Core Fin

A casting defect, a depression in the casting caused by a fin on the core that was not removed before the core was set, or by paste that has oozed out from between the joints.

Core Float

A casting defect caused by core movement towards the cope surface of the mold, as a result of core buoyancy in liquid steel, resulting in a deviation from the intended wall thickness.

Core Frame

Frame of skeleton construction used instead of a complete core box in forming intermediate and large cores.

Core Grinder

Machine for grinding a taper on the end of a cylindrical core or to grind a core to a specified dimension, usually flat face.

Core Gum

A pitch material used as a core binder.

Core Hardness

The ability of a core to resist scratching or abrasion.

Core Jig

A device for setting core assemblies outside of the mold and placing the whole assembly in the mold.

Core Knockout Machine

A mechanical device for removing cores from castings.

Core Lightener

A core material of any size and shape used to lighten pattern castings and match plates.

Core Maker

A core seat so shaped or arranged that the core will register correctly in the mold; also termed locator, indicator, register, telltale.

Core-Mading Machine

A device to make cores.

Core Mud

A daubing mixture used to correct defect in cores.

Core Prints

Portions of a pattern that locate and anchor the core in the proper position in the sand.

Core Refractiveness

The ability of a core to resist breakdown when exposed to heat.

Core Rod

A wire or rod of steel used to reinforce and stiffen the core.

Core Sand

Sand for making cores to which a binding material has been added to obtain good cohesion and permeability after drying. Usually low in clays.

Core Setting Jig/Gage

A device used to help position a core in the mold.

Core Setting Jig

A device used to help set a core into the mold.

Core Shift

A variation from specified dimensions of a cored section due to a change in position of the core or misalignment of cores in assembling.

Core Shooter

A device using low air pressure to fluidize the sand mix which is released quickly in such a way as to force it into a core box.

Core Spindle

A shaft on which a core barrel is rotated in making cylindrical cores.

Core Sprayer

A device for spraying a coating on cores.

Core Strainer (Strainer Tub)

Baked sand or refractory disc with uniform size holes through its thickness used to control the discharge of metal from pouring basins into sprues or to regulate the flow of metal in gates systems of molds; also to prevent entrance of dross or slag into the mold cavity.

Core Stickle Template (Sweep)

Device of wood or metal to give shape to certain types of cores or molds.

Core Truck

Truck or carriage used for transporting cores.

Core Vents

1) holes made in the core for escape of gas. 2) A metal screen or slotted piece used to form the vent passage in the core box employed in a core-blowing machine. 3) A wax product, round or oval in form, used to form the vent passage in a core.

Core Wires or Rolls

See Core Rod

Coreless Induction Furnace

See Induction Furnace

Coremaker

A craftsman skilled in the production of cores for foundry use.

Corer, Sag

A decrease in the height of a core, usually accompanied by an increase in width, as a result of insufficient green strength of the sand to support its own weight.

Coreroom

Department of the foundry in which cores are made.

Coring (Metallurgical)

Variable composition due to the solidification characteristics of an alloy. Typically these compositional differences occur on a micro scale, the distances between compositional extremes being controlled by the solidification structure of the alloy.

Coring Up

Placement of cores chills, and chaplets in mold halves before closing the mold.

Cornerslick (inside and Outside Corners)

A molder's tool used for repairing and slicking the sand in molds. Used primarily on Dry sand and loam.

Corrective Effective Temperature Chart

A chart on which information can be plotted resulting in an adjustment temperature reading more indicative of human comfort.

Corrosion

1) Gradual chemical or electrochemical attack on a metal by atmosphere, moisture or other agents, 2) chemical attack of furnace linings by gases, slags, ashes or other fluxes occurring in various melting practices.

Corrosion Index

A number expressing the maximum depth in mils to which corrosion would penetrate in one year on the basis of a linear extrapolation of the penetration occurring during the lifetime of a given test or service.

Corrosion Wear

Wear in which chemical or electrochemical reaction with the environment is significant.

Corundum

Native alumna, or aluminum oxide, Al2O3, occurring as rhombohedral crystals and also in masses and variously colored grains. Applied specifically to nontransparent kinds used as abrasives. It is hardest mineral except the diamond. Corundum and its artificial counterparts are abrasives especially suited to the grinding of metals.

Coslettizing

Producing a black, rust-resisting surface on iron and steel by boiling for some hours in water containing phosphoric acid and iron filings.

Cottrell Process

An electrostatic method of removing solid particles from gases.

Count Rate Meter

A device which gives a continuous indication of the average rate of ionizing events.

Couple

Two dissimilar conductors in electrical contact. An electromotive force in created under proper electrolytic influences or during heating.

Courses

Alternate layers of material in a pattern, or brickwork.

Cover

A protective blanket laid on a melt to exclude oxidizing atmosphere and in the case of magnesium to prevent its igniting. Neutral covers simply protect metal from atmosphere; reacting covers contain an agent such as a deoxidizer.

Cover Core

A core set in place during the ramming of a mold to cover and complete a cavity partly formed by the withdrawal of a loose part of the pattern. Also used to form part or all of the cope surface of the mold cavity. A core placed over another core to create a flat parting line.

Cover Half

In Die casting, the stationary half of the die.

Crab

See Core Crab

Crack, Hot Tear

A rupture occurring in a casting at or just below the solidifying temperature by a pulling apart of the soft metal, caused by thermal contraction stresses.
See also Quench Crack

Cracking Strip

A fin of metal molded on the surface of a casting to prevent cracking.

Crane

A machine for lifting heavy weights; may be hand or power operated. Type include electric, gantry, jib, monorail, etc.

Crane, Gantry

A bridge carrying a traveling crane and supported by a pair of trestles running on parallel tracks.

Crane, Jib

A crane suspended from a jib.

Crane, Mobile

A crane supported on structure that rolls on wheels; may be moved manually or by its own power.

Crane, Wall Jib

A jib crane mounted on a wall rather than on an overhead beam.

Craze Crack (Crazing)

Minute crack on ceramic or refractory surface caused by thermal or mechanical shock.

Crazing (Worming)

A defect found in pack-hardened tools, manifested in surface markings.

Creep

The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength. The effect is particularly important if the temperature of stressing is in the vicinity of the recrystallization temperature of the metal.

Creep Limit

The maximum stress that will result in creep at a rate lower than an assigned rate.

Crib

Network of cast iron used to support the cope when no cope flask is used.

Cristobalite

Simplest crystallographic form of SiO2.

Critical Cooling Rate

The minimum rate of continuous cooling just enough to prevent undesired transformations.

Critical Shear Stress

The shear stress required to cause slip in a single crystal, in a designated slip direction on a given slip plane. Referred to as the critical resolved shear stress if the shear stress reaches a threshold level.

Critical Strain

A term used in stress corrosion cracking tests to indicate the maximum strain rate necessary to promote stress corrosion cracks.

Comodizing

A rust-proofing process for steel.

Croning Process (C Process, Cronizing)

A casting process name after its German developer Johannes Croning. It is a precision production process using a phenol formaldehyde resin binder.
See Shell Molding

Cross Gate

See Runner

Cross Section

A view of the interior of an object that is represented as being cut in two, the cut surface presenting the cross section of the object.

Crossbar

Wood or metal bar placed in a flask to give greater anchorage to the sand than is afforded by its four walls.

Crown

Furnace roof, especially when dome-shaped; highest point of an arch.

Crucible

A ceramic pot or receptacle made of materials such as graphite or silicon carbide, with relatively high thermal conductivity, bonded with clay or carbon, and used in melting metals; sometimes applied to pots made of cast iron, steel, or wrought steel. The name derives from the cross (Crux) with which ancient alchemists adorned it.

Crucible Furnace

A furnace fired with coke, oil, gas, or electricity in which metals are melted in a refractory crucible.

Crucible Zone

The zone in the cupola between the bottom and the tuyere.

Crush

Buckling or breaking of a section of mold due to incorrect register when closing. Also, an indentation in the casting surface due to displacement of sand in the mold when the mold is closed.

Crush Strip or Bead

An indentation in the parting line of a pattern plate which ensures that cope and drag have good contact by producing a ridge of sand which crushes against the other surface of the mold or core.

Crystal

A physically homogeneous solid in which the atoms, ions, or molecules are arranged in a three-dimensional repetitive pattern.

Crystal Analysis

Determination of crystal structure.

Crystal Lattice

The way atoms are arranged in a crystal. Spacewise, there are only 14 different lattices.

Crystalline Fracture

Fracture of a brittle metal, showing definite crystal faces in the fractured surface.

Crystallization

The formation of crystals by the atoms assuming definite positions in the crystal lattice, e.g. when a metal solidifies.

Curing Time (No Bake)

That period of time needed before a sand mass reaches maximum hardness.

CTD

Cumulative Trauma Disorder. Illnesses that develop gradually over time and involve disorders of the soft tissues of the body. Caused or aggravated by repeatedly or constantly applied excessive forces, awkward postures, or highly repetitive movements of the body.

Cut

Defect in a casting resulting from erosion of the sand by metal flowing over the mold or cored surface.

Cutoff Machine, Abrasive

A device using a thin abrasive wheel rotating at high speed to cut off gates and risers from castings, or in similar operations.

Cutter, Gate

A scoop or other form of cutting gates in the mold.

Cutting Wheel

The plastic discs impregnated with an abrasive for cutting ceramics and metals. Used on abrasive cutoff machines.

Cyclone (Centrifugal Collector)

In air pollution control, a controlled descending vortex created to spiral objectionable gases and dust to the bottom of a collector core.

Cyclonic Scrubber

In air pollution control, radial liquid (usually water) sprays introduced into cyclones to facilitate collection of particles.

Cyclotron

A device for accelerating charged particles to high energies by means of an alternating electric field between electrodes placed in a constant magnetic field.

D (Fordath) Process

Shell molding in which the shell is made by blowing sand into a box like heated structure so that a shell of controlled thickness is created.

Datum Plane

In layout and machining operations the reference plane from which dimensions are measured in the perpendicular direction.

Datum Points

In layout and machining operations the reference points on a datum plane from which dimensions are measured.

Daubing

Filling of cracks in molds or cores by specially prepared pastes or coatings to prevent a mechanical penetration of metal into these cracks during pouring. Also, the final plastering or coating of the cupola or ladle after shrinkage has taken place during the drying period. Clay slurry or clay wash with various coating compounds are applied.

dB

See Decibel

DC (Direct Chill) Casting

A continuous method of making ingots or billets or extrusion by pouring the metal into a short mold. Some times called semi-continuous casting.

Dead Annealing

See annealing

Deadburned

Term applied to refractory materials obtained by calcining at a temperature high enough to form a product inert to atmospheric moisture and carbon dioxide, and less apt to contract.

Deadburned Dolonite

Dolonite burned at high temperature with additions of an agent, such as oxide of iron.

Deadhead

The useless metal projecting on a casting which corresponds to the position of a riser in the mold.

Dead Steel

Fully killed steel, also applied to steel which fails to respond to heat treatment.

Decant

1) Pour from one vessel to another, 2) pour off molten metal without disturbing the sludge.

Decarburiztion

Loss of carbon from the surface of a ferrous alloy as a result of heating in a medium, usually oxygen, that react with carbon.

Decibel (dB)

Unit for measuring the ration amounts of acoustical power; one-tenth of a bel.

Deep Etching

Macroetching; etching for examination at a low (less that 10X) magnification, in a reagent that attacks the metal to a much greater extent than normal for microscopic examination. Gross features my be developed; i.e., abnormal grain size, segregation, cracks, or grain flow.

Deepbed Filter

A gas filter in air pollution control, consisting of a loosely packed mat of fibrous materials; not practical where high grain loading are encountered.

Defect

A discontinuity in the product whose severity is judged unacceptable in accordance with the applicable product specification.

Deformation Test

An AGS test using an instrument such as the Dietert Universal Sand-Strength Testing machine (with deformation accessory) to determine the amount in inches that the sand specimen is compressed before it ruptures.

Degasser

A material employed for removing gases from molten metals and alloys.

Degassing

Usually a chemical reaction resulting from a compound added to molten metal to remove gases from the metal. Often inert gases are used in this operation.

Degassing Flux

A flux for removing gas from the melt.

Degree of Ramming

The extent of hardness to which a sand mold is rammed.

Delay Screen (Skim Gate (Erroneously), Skim Strainer)

A small piece of perforated light gage tinned sheet steel, or of copper, aluminum, and/or magnesium alloys, frequently placed in the pouring basin at the top of the downsprue. It delays the flow of metal long enough to allow the basin to fill before it melts to permit only clean metal from the bottom of the basin to enter the downsprue. Delay screens are also use elsewhere in the gating system.

Dendrite

A crystal of branched appearance, formed during solidification of alloys, the branching habit being controlled by specific crystallographic directions.

Densitometer

Instrument utilizing the photoelectric principle to determine the degree of darkening of developed photographic film.

Density

The mass per unit volume of a substance, usually expressed in grams per cubic centimeter or in pounds per cubic foot.

Density (Photographic)

Density is used to denote the degree of darkening of photographic film. Logarithm of opacity of exposed and processed film. Opacity is the reciprocal of transmission; transmission is the ratio of transmitted to incident intensity.

Dexidation

Removal of excess oxygen from molten metal, usually accomplished by adding materials with a high affinity for oxygen, the oxides of which are either gaseous or readily form slags.

Dephosphorization

Elimination of phosphorus from molten steel.

Dermatis

An inflammation of the skin, which may be caused by allergy to certain casting adjuncts, as resins; particularly in the shell process.

Descale

Remove the fire scale from the surface of casting.

Design Base Line

The noise spectrum which is the goal of any particular noise reduction program.

Designations

Type of metal named, as steel, malleable, nonferrous, etc.

Desulfurization

Removal of sulfur from the molten metal by addition of suitable compounds.

Desulfurizer

A material used to remove sulfur from molten metals and alloys. Also, a form of holding ladle or basin in which the molten metal and desulfurizing material are brought into contact.

Detroit Cup Test

A cupping test for sand, using a steel ball as plunger, the depth of cup being shown on a dial

DeVries Test

A test to give the relative hardness of deep hardening steels.

Dew Point

The temperature at which moist air will become saturated and condensation of water vapor will take place.

Dewaxing

The process of melting out the expendable was pattern from an investment mold by the application of heat, usually at temperatures less than 250°F (121)°C).

Dextrin

Soluble gummy carbohydrate formed by the decomposition of starch by heat, acids, or enzymes; it is use din core compounds, mold compounds, mold washes, core pastes, and other compounds requiring high dry compressive strengths.

Diameters

In microscopy, an indication of the amount of magnification. 1000 diameters=1000 times original size.

Diammonium Phosphate

Used to fireproof clothing of foundry workers.

Diaphragm Shell Molding Machine

An arrangement for applying a squeeze pressure with a high-temperature silicone rubber diaphragm.

Diaspore Clay

A rocklike mineral consisting chiefly of diaspore (HAlO2) bonded by fire clay substance with an alumina content higher than 63%.

Dia-Tester (Wolpert Hardness Tester)

A hardness testing machine using the Vickers or Brinell ball indenter.

Diathermometer

An instrument for examining the thermal resistance or the heat conducting power of objects.

Diatomaceous Earth (Infusorial Earth)

A hydrous of silica which is soft, light in weight and consists mainly of microscopic shells of diatoms or other marine organisms.

Die

A metal block used in forming materials by casting, molding, stamping, threading, or extruding.

Die Assembly

The parts of a die stamp or press that hold the die and locate it for the punches.

Die Casting (Brit. Pressure Die Casting)

A rapid, water-cooled permanent mold casting process limited to nonferrous metals. There are three types: the plunger-type operated hydraulically, mechanically or by compressed air with or without a gooseneck; the direct-air injection which forces metal from a goose-neck into the die, and the Cold-Chamber Machine. All force the metal into the die with a pressure greater than that of gravity flow.

Die Coating

See Release Agent

Die Insert

A removable liner or part of a die body or punch.

Die Sinking

Forming or machining a depressed pattern in a die.

Dielectric Oven (Dryer)

A rapid-drying high frequency electric oven used to bake cores.

Die Set

In stamping, the parts of the press that hold the die and locate it in proper relation to the punches.

Dietert Process

A patented process for the production of precision molds involving blowing a contoured core around a pattern to form half a mold.

Dietert Tester

A patented apparatus for the direct reading of a Brinell hardness after impression without using magnification or conversion tables.

Differential Heat Treatment

A heating process by which the temperature is varied within the object so that, after cooling, various parts may have different properties as desired.

Diffuser

X-ray equipment, a portion of the condensing and focusing system that permits even distribution of energy.

Dike

A patented flexible seal to prevent blow-by in core boxes.

Dilatometer

An instrument for measuring the length of a metal sample during heating and cooling.

Dimensional Tolerance Grades

A system of classifying the tightness of tolerances for the purpose of defining accurately the tolerances involved, and for simplifying the communication process between customer and producer regarding what is wanted, and what is possible, respectively.

Dip Coat

In solid and shell mold investment casting, a fine ceramic coating applied as a slurry to the pattern to produce maximum surface smoothness, followed by a cheaper conventional investment.
See Investment Precoat

Dip Tank

A tank, preferably lined with rubber, epoxy, or other nonmetallic, into which diecastings are dipped for cooling after leaving the machine.

Dipped Joint

A thin joint made by dipping of the brick in a thin mortar.

Direct-Arc Furnace

An electric arc furnace in which the metal being melted is one of the poles.

Direct Casting

Teeming from the ladle into the casting mold without the use of a tundish.

Dirt Trap

A well employed in a gating system to entrap the first metal poured, which may contain dirt or unwanted particles (ineffective).
See Slag Trap

Dirty Casting

A casting containing an excessive amount of nonmetallic inclusions in the body of the metal.

DIS

Ductile Iron Society

Disappearing Filament Pyrometer (Optical Pyrometer)

A telescope in which a hot body is viewed through an eyepiece; temperature is measured by the matching color of a calibrated lamp filament with color of hot metal.

Dispersed Shrinkage

Small shrinkage cavities dispersed through the casting, which are not necessarily cause for rejection.

Despersion Hardening

Hardening by the formation of hard microconstituents dispersed in a softer matrix.
See Preciptitation Hardening

Distruptive Strength

Maximum strength of a metal when subjected to three principal tensile stresses at right angles to one another and of equal magnitude.

Dissolved Carbon

Carbon in solution in steel in either the liquid or solid state.

Distorted Pattern

A pattern untrue to the specified dimensions.

Distortion

See Warpage

Distribond

A siliceous clay containing Bentonite used as bond in molding sands.

Distribution, Sand Grain

Variation or uniformity in particle size of a sand aggregate when properly screened by U.S. Standards screens.

Disturbed Metal

The cold worked metal formed on a polished surface during the processes of grinding and polishing.

Divorced Pearlite (Granular Perlite, Spheroidite, Spheroidized Cementite)

Pearlite in which the cementite has been spheroidized by prolonged annealing just below the Ac1 point, or by annealing at the same temperature after cold working.

Dolomite

A mineral calcium-magnesium carbonate (Ca, MG (CO3)2) used as a flux in iron melting and smelting; also as a base in refractors.

Dose

A quantity of radiation measured at a certain point expressed in roentgens, rems or rads.

Dose, Exposure

Quantity of radiation measured in air in roentgens without backscatter at a given point.

Dose Meter, Integrating

Ionization chamber and measuring system designed for determining total radiation administered during an exposure. In medical radiology the chamber is usually designed to be placed on the patient's skin. A device may be included to terminate the exposure when it has reached a desire value.

Dose Rate

Dose per unit time.

Dosimeter

Instrument used to detect and measure an accumulated dosage of radiation; in common usage it is a pencil-size ionization chamber with a built-in self-reading electrometer; used for personal monitoring.
See Dosimeter, Pocket

Dosimeter, Pocket

A pocket ionization chamber containing it own electrometer. An auxiliary charging device is usually necessary.

Double Annealing

As applied to hypoeutectoid steel, a process of heating to above the upper critical point (AC3) and holding at that temperature until complete solution of the carbide has been achieved then cooling rapidly and reheating immediately to above A3 and slowly cooling.

Double Impression Method

A way of determining approximate Brinell hardness by placing a hardened steel ball between a specimen of known hardness and the metal to be tested and pressurizing in an arbor press.

Double Skin (bottom Splash, Ingot Shell, Plaster)

A defect consisting of a secondary layer of metal sometimes found on top-poured ingots.

Double Tempering

A retempering operation sometimes necessary for steel containing retained austenite which breaks down during cooling from the first tempering to form a new and hence untempered martensite.

Doublebruned

Deadburn; not be mistaken for two firing.

Dowel

1) a wooden or metal pin of various types used in the parting surface of parted patterns and core boxes, 2) in diecasting dies, metal pins to ensure correct registry of cover and ejector halves.

Downcomer

In air pollution control, a pipe for conducting bases down into a conditioner and subsequent cleaning.

Downgate

See Downsprue

Downhand Welding

Welding deposited along a horizontal line and surface.

Downsprue (Sprue, Downgate)

The first channel, usually vertical, which the molten metal enters; so called because it conducts metal down into the mold.

Downtime

Time lost from normal casting activity, due to unscheduled interruptions.

Draft, Pattern

See Pattern Draft

Drag

Lower or bottom section of a mold or pattern.

Draw

A term used for 1) to temper, 2) to remove pattern from mold, 3) an external contraction defect on surface of mold.

Draw Peg

A wooden peg used for drawing patterns.

Draw Plate

A plate attached to a pattern to facilitate drawing of a pattern from the mold.

Draw Screw

A threaded rod with an eye screwed into a pattern to enable it to be drawn from the mold.

Draw Spike

A steel spike used to rap and draw a pattern from the sand; it is driven into the wood of the pattern, as opposed to a Draw Screw, which threaded.

Drawback

Part of a mold of green sand that may be drawn back to clear overhanging portions of the patterns.

Drawing

Removing pattern from the mold or mold from pattern in production work.
See also Temper

Dried Sand

Sand which bas been dried by mechanical dryer prior to use in core making.

Drier (Dryer)

A material, as alcohol ammonium nitrate, sodium perborate and manganese oleate, added to a core or mold mixture to remove or reduce the water content.

Drillings, Test

Chips, or small particles of metal removed from a test specimen for chemical analysis.

Drop (Dropout)

A casting defect caused by sand dropping from the cope or other overhanging section.

Drop Ball

A heavy weight, usually ball or pear shaped, dropped from a height to break large pieces of metal scrap. Also used to strengthen warp castings.

Drop Gate

A term for a pouring gate or runner leading directly into the top of the mold.

Drop Off or Drop Out

Sand falling from the Cope of a mold.
See Drop

Drum Ladle

A cylindrical refractory-lined ladle that is completely enclosed. A removable cover at the pouring spout permits addition of molten metal.

Drum, Magnetic

An electrically energized pulley or drum used for removing magnetic materials from sand, nonferrous borings and turnings, etc.

Dry Analysis

A term applied to spectrographic analysis.

Dry and Baked Compression Test

An AFS test to determine the maximum compressive stress that a baked sand mixture is capable of developing.

Dry Pan

A grinding machine of heavy rollers or millers testing on a bed. Screens or slits allow fine material to pass through.

Dry Permeability

The property of a molded mass of sand bonded or unbonded, dried at 220-230°F (105-110°C) and cooled to room temperature that allows passage of gases resulting during pouring of molten metal into a mold.

Dry Sand Casting

The process in which the sand molds are dried at above 212°F (100°C) before using.

Dry Sand Core

See Core

Dry Sand Mold

A mold from which the moisture has been removed by heating.

Dry Strength, or Dry Bond Strength

The maximum compressive, shear, tensile, or transverse strength of a sand mixture which has been dried at 220 to 230°F (105 to 110°C) and cooled to room temperature.

Dryer, Core

See Core Driers

Dryer, Dielectric

See Dielectric Oven

Dual Metal Centrifugal Casting

Centrifugal castings produced by pouring a different metal into the rotating mold after the first metal poured.

Dust

Small solid particles created by the breaking up of larger particles by an process.

Ductile Iron

See Nodular Iron

Ductile Iron Society

Ductile Iron Society

Eddy Current Testing

The detection of discontinuities by observation of the interaction between electromagnetic fields and metals.

Elastic Limit

Maximum stress that a material will withstand without permanent deformation.
See Yield Strength

Elasticity

The property of recovering original shape and dimensions upon removal of a deforming force.

Electrical Precipitator

In air pollution control, the use of electrodes in stack emissions emitting high voltage; particles 0.1 micron and smaller can be attached and collected at discharge electrode.

Electrochemical Corrosion (Contact corrosion, Electrolytic corrosion, Galvanic corrosion)

Localized corrosion from exposure of an assembly of dissimilar metals in contact or coupled with one another, i.e., electrochemical action.

Electrode

Compressed graphite or carbon cylinder or rod used to conduct electric current in electric arc furnaces, arc lamps, carbon arc welding, etc.

Electron Microprobe Analyzer

An instrument for selective analysis of a microscopic area, in which an electron beam bombards the point of interest in Vacuo at a given energy level. Intensity of backscatter is measured to interpret which chemical elements are present, and by scanning a large area the microprobe can analyze chemical composition and indicate the distribution of an element.

Elongation

Amount of permanent extension in the vicinity of the fractures in the tensile test; usually expressed as percentage of original gage length.

Embrittlement

Loss of ductility of a metal due to chemical or physical change.
See Acid Embrittlementand Hydrogen Embrittlement

End-Quench Hardenability Test

A standardized method for comparing the hardenability of different steels.

Endothermic Reaction

The reaction which occurs with absorption of heat.

Engineering Strain (e)

The average linear strain, obtained by dividing the elongation of the length of the specimen by the original gage length.

Engineering Stress (s)

The load divided by the original area.

EPC (Expendable Pattern Casting)

See Lost Foam Process.

Equilibrium

A dynamic condition of balance between atomic movements, where the resultant is zero and the condition appears to be one of rest rather than change.

Ergonomics

The science which deals with the interaction between people, their work place and environment. It also considers the physiology of workers in the design of tools, equipment, and the work methods needed.

Erosion

Abrasion of metal or other material by liquid or gas, usually accelerated by pressure of solid particles of matter in suspension, and sometimes by corrosion.

Etchant

A solution for chemical etching the polished surface of a metal specimen to reveal macro- or micro-structures.

Eutectic

1) An isothermal reversible reaction in which a liquid solution decomposes, on cooling, into two or more intimately mixed solids. The number of solids formed are the same number of components in the system. 2) An alloy having the chemical composition indicated by the eutectic point on a equilibrium diagram.

Eutectoid

1) An isothermal reversible reaction in which a solid solution on cooling is converted into two or more intimately mixed solids. The number of solids formed are the same number of components in the system. 2) An alloy having the same chemical composition indicated by the eutectoid point on a equilibrium diagram.

Evaporation Pattern Casting / Expendable Pattern Casting / EPC

See Lost Foam Process.

Exothermic

Formed by or characterized by heat reaction as in oxidation.

Exothermic Reaction

Chemical reactions involving the liberation of heat.
See Endothermic Reaction.

Extensometer

An instrument used in the testing of metals to measure small increments of deformation.

Fabrication

The joining, usually by welding, of two or more parts to produce a finished assembly. The components of the assembly may be a combination of cast and wrought materials.

Facing Sand

Specially prepared molding sand mixture used in the mold adjacent to the pattern to produce a smooth casting surface.

Fatigue

The loss of load-bearing ability of a material under repeated load application, as opposed to a single load.

Fatigue Crack or Failure

A fracture starting from a nucleus where there is an abnormal concentration of cyclic stress. The fracture surface is smooth and frequently shows concentric (sea shell) markings with a nucleus as a center.

Fatigue Limit (Endurance Limit)

Maximum stress that a material will endure without failure for an infinite number of load cycles.

Fatigue Strength

Maximum stress that a material will endure without failure for a specified number of load cycles.

Feeding

The process of supplying molten metal to compensate for volume shrinkage while the casting is solidifying.

Ferrite

A solid solution of one or more elements in the body-center-cubic phase of iron or steel.

Ferritic Steels

Steels in which ferrite is the predominant phase. These steels are magnetic.

Ferromagnetic

The ability to become highly magnetic and have the ability to retain a permanent magnetic moment. The elementary magnetic dipoles inside the domain are all oriented in a direction parallel to each other.

Fettle

British term meaning the process of removing all runners and risers and cleaning off adhering sand from the casting. Also refers to the removal of slag from the inside of the cupola and in Britain to repair the bed of an open hearth.

Fillet

A concave corner piece used on foundry patterns, a radius joint replacing sharp inside corners.

Finish Allowance

The amount of stock left on the surface of a casting for machining.

Finish Mark

A symbol (f, f1, f2, etc.) appearing on the line of a drawing that represents the edge of the surface of the casting to be machined or otherwise finished.

Finish Welding

Production welding carried out in order to ensure the agreed quality of the casting.

Finite Difference Analysis (FDA)

A computerized numerical modeling approach for solving differential equations. Used primarily in solving heat transfer and solidification problems.

Finite Element Analysis (FEA)

A computerized numerical analysis technique used for solving differential equations to primarily solved mechanical engineering problems relating to stress analysis.

Firecracker Core

See Pencil Core

Flame Hardening

A surface hardening process involving localized flame heating to above the austenite transformation temperature, Ac3, followed by quenching.

Flash

A thin section of metal formed at the mold, core, or die joint or parting in a casting due to the cope and drag not matching completely or where core and coreprint do not match.

Flask

A metal frame used for making or holding a sand mold. The upper part is the cope and the bottom half is the drag.

Flask Bar

A reinforcing member attached within either half of a flask to assist in holding the rammed sand in position.

Flask Clamp

A device for holding together the cope, drag, and cheek of a flask.

Flask Pin Guides

Guides used to accurately align the match plate pattern in the flask and flask to flask location.

Flat Back

A pattern with a flat surface at the joint of the mold. It lies wholly within the drag and the joint of the cope is a plane surface.

Flow-Off (Pop-Off)

A large vent, usually located at the high of the mold cavity. In addition to letting air and mold gases escape as metal fills the mold cavity, the flow-off fills with metal and acts to relieve the surge of pressure near the end of the pouring.

Fluidize

To impart fluid like properties to powders or sands e.g. fluidized beds.

Fluidity

The ability of molten metal to flow. Common devices used to measure fluidity are: spiral casting and the Chinese Puzzle.

Foundry Returns

Metal in the form of sprues, gates, runners, risers and scrapped castings, with known chemical composition that are returned to the furnace for remelting. Sometimes referred to as "revert".

Frictional Wear

The displacement and/or detachment of metallic particles from a surface as a consequence of being in contact with another moving component.

Froude Number

Used in hydraulics as an analog to the Reynolds number. It is the ratio of inertial forces to gravitational forces.

Gage Length

The original length of that portion of the specimen over which strain or change of length is determined.

Gage Marks

Reference marks; in tensile testing, the marks which indicate the gage length, used in determination of tensile elongation.

Gaggers

Metal pieces of irregular shape used to reinforce and support the sand in the mold.

Gaging

Checking dimensional requirement by means of a gage.

Gamma Iron

A face-centered cubic form of pure iron, stable from 1670 to 2551°F (910 to 1400°C).

Gannister

An acid (silicious) refractory often used in furnace linings.

Gate

The end of a runner in a mold where molten metal enters the mold cavity.

Gating System

The complete assembly of sprues, runners and gates in a mold through which steel flows before entering the casting cavity.

Gouging Abrasion

Abrasion involving gross surface indentation and possible removal of sizable metal fragments.

Grain Fineness Number

A system developed by AFS for rapidly expressing the average grain size of a given sand. It approximates the number of meshes per inch of that sieve that would just pass the sample if its grains of uniform size. It is approximately proportional to the surface area per unit of weight of sand, exclusive of clay.

Granular Fracture (Crystalline Fracture)

A type of irregular surface produced when metal is broken.

Green Sand

A naturally bonded sand or a compounded molding sand mixture which has been tempered with water for use while still in the damp or wet condition.

Green Sand Core

A sand core used in the unbaked condition, also a core made from green sand and used as rammed.

Green Strength

The strength of a tempered sand mixture at room temperature.

Hadfield Manganese Steel

A specially steel which is austenitic and usually contains approximately 12% Manganese. It is used in mining, earth- moving equipment and in railroad track work.

Hardenability

In a ferrous alloy, the property that determines the depth and distribution of hardness induced by quenching.

Hardness

Resistance of a material to indentation as measured by such methods as Brinell, Rockwell, and Vickers. The term hardness also refers to stiffness of a material, or its resistance to scratching, abrasion, or cutting.

Head Metal

The reservoir of metal in the feeder or riser of a mold.

Heat

The total amount of metal produced which can be represented by one analysis sample and one set of mechanical tests.

Heat Treatment

A combination of heating and cooling operations and applied to a metal or alloy to produce desired properties and microstructures.

High-Alloy Steel

Ferrous alloy with more than 12 weight percent of noncarbon additions.

High Pressure Mold

A strong high-density mold, made by air, hydraulic, or other squeeze process.

High Stress Grinding Abrasion

Abrasion that occurs when the abrasive is crushed between two opposing surfaces.

Hindered Contraction

Casting contraction during solidification and cooling which is hindered by mold or core restraints.

Hollow Drill Test (Trepanning)

Removing a cylindrical sample from a metal section or structure to determine soundness of the section.

Homogenizing

A process of heat treatment at high temperature intended to eliminate or decrease chemical segregation by diffusion.

Horizontal Axis Casting Machine

A centrifugal casting machine in which the axis of rotation of the mold is horizontal.

Hot Box Process

A furan resin-based process similar to shell coremaking; cores produced with it are solid unless mandrelled out.

Hot Strength (Sand)

Tenacity (compressive, shear or transverse) of a sand mixture determined at any temperature above room temperature.

Hot Tear

A crack or fracture formed prior to completion of metal solidification as a result of hindered contraction. A hot tear is frequently open to the surface of the casting and is commonly associated with design limitations.

HSLA

High Strength Low Alloy Steel. Steel with relatively high strength and impact properties. The carbon level is low and the alloying additions are significantly less than 5 weight percent.

Hydrogen Embrittlement

A condition of low ductility resulting from the absorption of hydrogen. A time dependent fracture process which results in a loss of ductility.

Hypereutectoid Steel

A steel containing more than the eutectoid percentage of carbon (0.83 wt. %).

Hypoeutectoid Steel

A steel containing less than the eutectoid percentage of carbon (0.83 wt. %).

Hysteresis (Cooling Lag)

Difference between the critical points on heating and cooling due to tendency of physical changes to lag behind temperature changes.

Ideal Critical Diameter, DI

The largest diameter of a bar which, upon quenching in an ideal quench, will exhibit 50% martensite at the center of the bar.

ICI

Investment Casting Institute

ID Grinding

Term for internal (dimension) grinding.

Ideal Critical Diameter, D1

The largest diameter of a bar which, upon quenching in an ideal quench, will exhibit 50% martensite at the center of the bar.

Ideal Quench

A quench in which the temperature of an object being quenched instantaneously drops to that of the quench bath and remains constant.

Illinois Inclusion Count Method

A determination of the index number of cleanliness of steel.

Illite

A mineral, typically KAl3Si3O10(OH)2, found in many clays, large working of which are found in Illinois and Michigan.

IM and AWI

See International Molders and Allied Workers Union

Impact Strength

The resistance to impact loads; usually expressed as the foot pounds of energy absorbed in breaking a standard specimen.
See Charpy Impact Test.

Impact Value

Total energy needed to break a standard specimen by a single blow under standard conditions; e.g., Charpy Impact Test.

Impoverishment

Loss of any constituent from an alloy or from localized areas of an alloy by oxidation, liquidation, volatilization, or changes in the solid state. The term depletion is also used, particularly in referring to the lowering of the concentration of solute in a solid solution, around particles precipitated from solid solution.

Impregnation

The treatment of castings with a sealing medium to stop pressure leaks, such as soaking under pressure with or without prior evacuation and either with hot or cold application. Mediums used include silicate of soda, drying oils with or without styrene, plastics, and proprietary compounds.

Impurity

An element unintentional allowed in a metal or alloy. Some impurities have little effect on properties; others will grossly damage the alloy.

Inclusions

Nonmetallic materials in a metal matrix. Sources include reoxidation, refractories, slag, and deoxidization products.

Inconel

An oxidation-resistant alloy, 80% Ni, 14% Cr, and 6% Fe.

Indentation Hardness

The resistance of a material to indentation. This is the usual type of hardness test, in which a pointed or rounded indenter is pressed into a surface under a substantially static load.
See Brinell Hardnessand Hardness

Indirect-Arc Furnace

An AC (Alternating Current) electric-arc furnace in which the metal is not one of the poles.

Induction Furnace

A AC melting furnace which utilizes the heat of electrical induction.

Induction Hardening

A surface hardening process involving the localized use of pulsating magnetic currents to achieve heating above the austenite transformation temperature, Ac3, followed by quenching.

Induction Heating

Process of heating by electrical resistance and hysteresis losses induced by subjecting a metal to the varying magnetic field surrounding a coil carrying an alternating current.

Inert Gas

A gas that will not support combustion or sustain any chemical reaction; e.g., argon or helium.

Infrared Radiation Pyrometer

This instrument which uses the ratio of the radiated energy from a body in two wavelength bands and then is a measure of the body's surface temperature. Temperatures down to 200 C (392 F) may be measured.

Infrared Rays

Pertaining to or designating those rays which lie just beyond the red end of the visible spectrum, such as are emitted by a hot non-incandescent body. They are invisible and nonactinic and are detected y their thermal effect. Their wave lengths are longer than those of visible light and shorter than those of radio waves. Can be applied in the foundry for drying or core baking operations and for heating dies. Infrared radiant heat are synonymous.

Infrared Dryer

A core or mold dryer employing infrared lamps.

Infusorial Earth (Diatomite, Fossil Flour, Mountain Meal, Mountain Flour, Tripolite, Kieselguhr)

A very fine whitish powder composed of the siliceous skeletons of infusorians (Protozoa).

Ingates

The channels through which molten metal enters the mold cavity.
See Gate

Ingot

A mass of metal cast to a convenient size and shape for remelting or hot working.

Ingot Iron

Iron of comparatively high purity produced in open-hearth furnace under conditions that keep down the carbon, manganese, and silicon content; e.g., Armco Iron

Injection Molding

The injection of molten metal or other material under pressure into molds.

Inoculant

Material which when added to molten metal modifies the structure, and thereby changes the physical and mechanical properties to a degree not explained on the basis of the change in composition resulting from its use.

Inoculation

Addition to molten metal of substances designed to form nuclei for crystallization.
Also see Inoculant

Insert

A part usually formed from metal, which is placed in a mold and may become an integral part of the casting.

Insulating Pads and Sleeves

As opposed to chills, insulating material, such as gypsum, diatomaceous earth, etc., used to lower the rate of solidification. As sleeves on open risers, they are used to keep the metal liquid, thus increasing the feed efficiency.

Integral Dose (Volume Dose)

A measure of the total energy absorbed by man or any object during exposure to radiation.

Intensity (Radiology)

Amount of energy per unit time passing through a unit area perpendicular to the line of propagation at the point in question. Often this term is used incorrectly in the sense of dose rate.

Intercast Process

A patented procedure for die casting " cast-assemble " units with moving parts.

Intercrystalline Failure

Cracks or fractures that follow along the grain boundaries in the microstructure of metals and alloys.

Interdendritic Attack

A type of electrochemical corrosion that sometimes occurs in as-cast alloys or alloys that have had very little working.

Intergranular Corrosion

Corrosion in a metal taking place preferentially along the grain boundaries.

Internal Friction

Ability of a metal to transform vibratory energy into heat; generally refers to low stress levels of vibration; damping has a broader connotation since it may refer to stresses approaching or exceeding yield strength.

Internal Shrinkage

A void or network of voids within a casting caused by inadequate feeding of that section during solidification.

Internal Stresses (or Thermal Stresses)

Generally stresses which occur during the cooling of a part.

Interrupted Quench

Removing the casting from a quenching bath before it has reached the temperature of the bath.

Invar

An alloy having practically no expansion when heated; 36% Ni, 0.5% Mn, 0.2% C, and the balance Fe.

Inverse Segregation

A concentration of certain alloy constituents that have lower melting points in the region corresponding to that first solidifying; caused by interdendritic flow of enriched liquid through channels where the pressure drops with contraction of dendrites. The internal evolution of hydrogen may also give a positive pressure, aiding this flow and causing a liquidated surface as tin sweat.
See also Segregation

Inversion

A change in crystal form without change in chemical composition, as from quartz to cristobalite.

Inversion Casting

1) The metal is fed through a bottom feeder, the mold being inverted for pouring, 2) the mold is directly attached to the electric furnace in which the metal is melted in a reducing atmosphere so no slag is formed. On inverting the furnace the metal runs into the mold. There are no heavy feeders and oxidation is prevented.

Investing

The process of pouring the investment slurry into the flask surrounding the pattern to form the mold.

Investment

A flowable mixture of a graded refractory filler, a binder and a liquid vehicle which when poured around the patterns conforms to their shape and subsequently set hard to form the investment mold.

Investment Casting

Casting produced in a mold obtained by investing an expendable pattern with a refractory to produce a shell. The expendable pattern may consist of wax, plastic, or other material and is removed prior to filling the mold with liquid metal.

Investment Precoat

An extremely fine investment coating applied as a thin slurry directly to the surface of the pattern to reproduce maximum surface smoothness. The coating is surrounded by a coarser, cheaper, and permeable investment to form the mold.
See Dip Coat

Inwall Brick

Refractory lining of the inwall section of blast furnace or cupola.

Ionization

The process or the result of any process by which a neutral atom or molecule acquires either a positive or a negative charge.

Ionization Chamber

An instrument designed to measure quantity of ionizing radiation in terms of the charge of electricity associated with ions produced within a defined volume.

Iridium

A noble metal of the platinum group. Usually extensively as a radiation source. For radiography of thin walled castings.

Iron

1) A metallic element, mp 1535 C (2795 F), 2) irons not falling into the steel categories, as Gray Iron, Ductile Iron, Malleable Iron, White Iron, Ingot, and Wrought Iron.

Iron Carbide

See Cementite

Iron, Hard or White

Irons (Fe3C) possessing white fracture because all or substantially all of the carbon is in the combined form. Irons to be malleablized are cast white, as are many abrasion-resistant irons.

Iron-Iron Carbide Diagram

A phase diagram representing metastable equilibrium conditions between Fe and Fe3C over the entire range of carbon steels and cast irons.

Iron-Carbon (Graphite) Diagram

A diagram representing stable equilibrium conditions between iron and graphite (pure carbon) phase over the entire range of iron and steel.

Iron, Malleable

A mixture of iron and carbon, including smaller amounts of silicon, manganese, phosphorus, and sulfur, which after being cast (white iron, carbon in combined form as carbides) is converted structurally by heat treatment into a matrix of ferrite containing nodules of temper carbon (graphite).

Iron Oxide

This material as prepared for foundry use generally contains about 85% ferric oxide and is produced by pulverizing a high grade of pure iron ore. It can be added to core sand mixes to assist in keeping the core from cracking before the metal solidifies during the casting operation and also helps to resist metal penetration during this period. Added to molding sand mixtures for control of finning and veining. Also may reduce carbon pick up.

Iron, Pearlitic Malleable

A malleable iron having a more or less pearlitic matrix.

Iron Sand

See Iserine

Iserine

A black sand which consists mainly of magnetic iron ore but also contains a considerable amount of titanium.

ISO

International Standards Organization.

Isocure

Proprietary name for a binder system developed for use in Ashland (Cold Box) Process, itself a proprietary process.

Isocyanate Acid

Isomeric cyanic acid (HNCO).

Isomorphous

Phases with crystal structures of the same type.

Isothermal

Pertaining to changes or other phenomena occurring at a constant temperature.

Isothermal Annealing

A process in which a ferrous alloy is heated to produce a structure partly or wholly austenitic, and is then cooled to and held at a temperature that causes transformation of the Austenite to a relatively soft ferric-carbide aggregate.

Isothermal Transformation

1) The process of transforming Austenite in a ferrous ally to Ferrite or a ferrite-carbide aggregate at any constant temperature within the transformation range, 2) transformation of one phase in an alloy system to another phase at any constant temperature.

Isotope

One of several different nuclides having the same number of protons in their nuclei, and hence having the same atomic number, but differing in the number of neutrons and therefore in the mass number.

J

1) Symbol for 1 gram equivalent weight, 2) the mechanical equivalent of heat.

Jack Arch

A spring arch, flat or horizontal on the underside.

Jamb

Usually an upright structural member forming the side of an opening in a refractory or furnace wall.

Jamb Brick

A brick modified so one corner is rounded.

Jar Ramming

Packing sand in a mold by raising and dropping on a table the sand, pattern, and flask. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle.

Jersey Fireclay Brick

Highly siliceous clay brick, semisilica brick.

Jet Scrubber

IN air pollution control, a high velocity water jet directed into the throat of a venture section of a cupola to separate out particulates.

Jet Tapping

A method of tapping a melting furnace by firing a small explosive charge instead of using an oxygen lance. The tapper consists of an explosive charge enclosed in a plastic case surrounded by a hollow bullet-shaped body.

Jib

Projecting part of crane from which lifting chain or gear is suspended.

Jig

Any device so arranged that it will expedite a hand or a machine operation.

J-Integral

A mathematical expression used to characterize the fracture toughness of a material having appreciable plasticity prior to fracture. The J-integral eliminates the need to describe the behavior of the material near the crack tip. Units are MN/m or in in-lb/in2.

Jobbing Foundry

A foundry engaged in the manufacture of numerous types of castings.

Joint Welding

Production welding used to weld cast components together to obtain an integral unit.

Jolt Ramming

See Jar Ramming

Jolt-Squeezer Machine

A combination machine that employs a jolt action followed by a squeezing action to compact the sand around the pattern.

Jominy Test

See End-Quench Hardenability Test

K

Symbol used in linear elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation, the factor is call the critical stress-intensity factor (KIc) or fracture toughness. Various subscripts denote loading conditions or fracture toughness. Units are Mpa/mm or ksi/in

K Factor

Tensile strength in pounds per square inch divided by the Brinell Hardness number.

Kahlbaum Iron

An iron of more than 99.975% purity, produced in Germany.

Kalling-Dommarfvet Process

A desulfurizing process using powdered burnt iron.

Kaolin

The purest form of China clay consisting of silicate of aluminum.

Kappa Carbide

A carbide of iron (Fe23, C6) in which all or part of the iron may be replaced by chromium, molybdenum, and/or tungsten.

Kayser Hardness Test

A method for determining the true hardness of metals at high temperatures.

KC (Plane-stress fracture toughness)

The value of stress intensity at which crack propagation becomes rapid in sections thinner than those in which plane-strain conditions prevail. Units are MPa/m or ksi/in.

Kelvin Temperature Scale

One in which the unit of measurement equals that of the centigrade degree and according to which absolute zero is 0 degrees, equivalent to -273.16 C.

Kerf

The width of a cut.

Keyhole Specimen

A type of notched impact test specimen which has a hole-and-slot notch shaped like a keyhole.

KIc (Plane-strain fracture toughness)

The minimum value of KC. Represents the fracture toughness of a material independent of crack length, or loading system. Units are MPa/m or ksi/in.

Kieselguhr

Diatomaceous earth, a finely porous material used for thermal insulation to 1100 C (2012 F).

Kiln

An oven or furnace for burning, calcimining or drying a substance.

Kiln-Dried

Lumber artificially dried in a specially designed enclosure or lumber kiln.

Kiln Marks

Irregularities on the surface of refractors caused by deformation under load during burning.

Kilovolt (kV)

Unit of electrical potential equal to 1,000 volts.

Kilovolts Constant Potential

The potential in kilovolts of a constant voltage generator.

Kilovolts Peak

The crest value of the potential wave in kilovolts. When only one half of the wave is used, the crest value is to be measured on this half of the wave.

Kip

A term sometimes used to represent a unit load of 1,000 lb.

Kish

Free graphite which separates upon slow cooling of molten hypereutectic iron.

Kissing (Touching)

Gating with minimum metal left at casting breakoff point, having a gate just "kiss" the surface.

Knockout Pins (Ejector Pins)

Small diameter pins affixed to a pattern back-up plate for removing cured mold in the shell-molding process.

Knoop Hardness Number (HK)

A number related to the applied load and to the projected area of a rhombic-based diamond indentor, with edge angles of 172° 1/2 30' and 130° 1/2.

Ladle

Metal receptacle frequently lined with refractories used for transporting and pouring molten metal. Types include hand bull, crane, bottom-pour, holding, teapot, shank, lip-pour.

Ladle, Bottom-Pour

Ladle from which metal flows through a nozzle in the bottom.

Ladle, Bull

A large ladle for caring molten metal. Frequently used to designate a transfer ladle.

Ladle, Lip-Pour

Ladle in which the metal is poured over a lip.

Ladle, Teapot

A ladle in which, by means of an external spout, metal is removed from the bottom rather than the top of the ladle.

Lance, Oxygen

A device, consisting of steel pipe, tubing, oxygen source, and controls which uses the heat of burning steel pipe for melting. Frequently used to open frozen tape or slag holes.

Lateral Expansion

A measured property used in Charpy Impact Testing. Refers to the increase width of the specimen after fracture.

LEFM (Linear Elastic Fracture Mechanics)

A method of fracture analysis that can determine the stress required to induce fracture instability in a structure with a crack like flaw of know size and shape.

Lining

Inside refractory layer of firebrick, clay, sand, or other material in a furnace or ladle.

Lining, Monolithic

A lining made without the customary layers and joints of a brick wall. Usually made by tamping or casting refractory material into place, drying, and then burning in place on the job.

Liquid Penetrant Testing

A nondestructive testing method suitable for evaluating the surface integrity of non-magnetic and ferro-magnetic parts.

Logo

The sign, mark, or distinguishing letter designating the manufacturer.

Loose Molding

The molding process utilizing unmounted patterns. Gates and runners are usually cut by hand.

Loose Piece

1) Core box: part of the core box which remains embedded in the core and is removed after lifting off the core box. 2) Pattern: laterally projecting part of a pattern so attached that it remains in the mold until the body of the pattern is drawn. Back-draft is avoided by this means. 3) Permanent mold: part which remains on the casting and is removed after the casting is ejected from the mold.

Lost Foam Process

Casting process in which a foam pattern is removed fro the cavity by the molten metal being poured.

Low Stress Scratching Abrasion

Abrasion involving near zero impingement angle for the striking particle, also parallel flow erosion.

Manganese Steel (Austenitic)

See Hadfield Manganese Steel

Machine Allowance

Stock added to the part to permit machining of the part to final dimensions.

Machine Drawing

An engineering drawing which depicts the final size and shape of the part for its end use.

Magnetic Particle Inspection

A nondestructive method of inspecting the surface integrity of ferromagnetic materials.

Maraging Steel

A high alloyed steel that is hardened by both martensite transformation and by age hardening.

Martempering (Interrupted Quenching)

A hardening treatment of a steel involving a slow cool through the martensitic transformation range to reduce stresses associated with the quenching of austenite. An important aspect of martempering is that no transformation product other than martensite should form.

Martensite

A generic term used for microstructures formed by diffusionless phase transformations. A constituent found in hardened steel; has a needle like microstructure.
See also Mf and Ms.

Martensitic Stainless Steels

A corrosion-resistant ferrous alloy with a predominant martensitic phase. Mass Effect… The effect that the mass of a component has on the properties of the material from which the part is made. In castings, such effects may arise due to the effect of mass on the solidification rate and on the rate of temperature change during heat treatment.

Mass Effect

The effect that the mass of a component has on the properties of the material from which the part is made. In castings such effects may arise due to the effect of mass on the solidification and on the rate of temperature change heat treatment.

Matchplate

A plate of metal or other materials on which patterns and gating systems, split along the parting line, are mounted back to back to form an integral piece.

Meallographic Structure

The nature, distribution, and amounts of the metallographic constituents in a metal.

Mechanical Properties

Properties of a material that reveal its strength and elastic behavior.

Metalloid

1) An element intermediate between metals and nonmetals possessing both metallic and nonmetallic properties, as arsenic, 2) sometimes applied to elements commonly bonded in small amounts in steel, as carbon, manganese, boron, silicon, sulfur, and phosphorus.

Metallstatic Pressure

A compound phase referring to hydrostatic pressure, substituting Metall since Hydro connotes water.

Metallurgical Bond

The bond between two metals whose interface is free of voids, oxide films, or discontinuities.

Metallurgy

The science and technology of metals, a broad field that includes but is not limited to the study of internal structures and properties of metals and the effects on them of various processing methods.

Metalock

A method of cold repair of castings and forgings.

Metals Comparator

An instrument for testing or identifying metallic and nonmetallic parts. Parts are placed in an electromagnetic field and a standard parts in a matched electromagnetic field. Distortions of the magnetic fields are compared on an oscilloscope.

Metamic

A metal ceramic high in Cr-Al2O3.

Metastable (Unstable)

A state of pseudo-equilibrium.

Mexico Bay Sand

A sand similar to Michigan City dune sand mined at Selkirk Beach, near Mexico NY., on Lake Ontario. It has a silica content of 90% and over.

Meyer Hardness Test

A test to determine tendency of a metal to harden when deformed plastically. A series of indentations are made in the metal using a fixed-diameter ball and progressively increasing loads.

Mf

The temperature at which martensite formation finishes during cooling.

Mica Schist

A type of micaceous refractory rock used for lining cupolas and other melting furnaces.

Mica Strainer

A skim core made of thin mineral silicates crystallizing in monoclinic form.

Michigan Sand

Core sands of dune or lake sand and bank sands found in Michigan.

Micro Pipes (Brit.) (Microshrinkage)

Tiny cavities, a fraction of a millimeter in diameter, with irregular outlines, which occur in castings. Etching shows they occur at intersections of convergent dendritic directions.

Microcast Process

A patented method of precision-casting alloys, as Vitallium, Monel, Inconel and the Haynes Stelite alloys.

Microetching

Etching of metal samples for examination under the microscope.

Microformer

A type of extensometer for measuring elongation of test piece in a tensile test.

Micrography

Examination by means of a microscope.

Microhardness

The hardness of microconstituents of a material.

Microinch

0.000001 (1/1,000,000th) of an inch. A common unit of measurement in surface measurement research and in standard roughness (surface) unit values of performance of machinery.

Microlug

A test coupon used to give rapid indication of the effectiveness of magnesium treatment of ductile iron.

Microporosity

See Microshrinkage

Microradiography

The process of passing x-rays through a thin section of an alloy in contact with a photographic emulsion, and then magnifying the radiograph 50 to 100 times to observe the distribution of alloying constituents and voids.

Microscopic

Minute object or structures which are invisible or not clearly distinguished without the use of a microscope.

Microsection

A metal specimen whose surface has been polished and etched to reveal the microstructure.

Microshrinkage

Very finely divided porosity resulting from interdendritic shrinkage resolved only by use of the microscope; may be visible on radiographic films as mottling. Etching shows they occur at intersections of convergent dendritic directions.

Microspectroscopy

A method of identifying metallic constituents using spectrographic arc.

Microstructure

The structure of polished and etched metal and alloy specimens as revealed by the microscope at magnifications over 10 diameters.

Micro-Tester

A low load hardness tester, suitable for both Vickers and Knoop tests, working with loads of between 10 to 3000 grams.

Microtone (Brit.)

An instrument for cutting thin sections of soft specimens.

Migra Iron (Brit.)

A special pig iron for high quality castings.

Mikro-Tester

A low load hardness tester, suitable for both Vickers and Knoop tests, working with loads of between 10 to 3000 grams.

MIL STD

United States Government military standards, specifications, usually requiring rugged, exacting testing equal to the exigencies of combat usage.

Mild Steel

Plain carbon steel of about 0.25% carbon or less.

Mill Scale

Iron oxide scale formed on steel during hot working processes, cooled in air

Mill Stars

Multi-pointed white iron or hard iron bodies used in a Tumbling Barrel to assist in polishing and cleaning.

Milling

Removing metal with a milling cutter.

Milliroentgen (mr)

A sub-multiple of the roentgen equal to one-thousandth (1/1000th) of a roentgen.

Milliscope (Brit.)

An instrument which gives an electrical warning when melt reaches a predetermined temperature.

Mineral

Natural inorganic substance which is either definite in chemical composition and physical characteristics or any chemical element or compound occurring naturally as a product of inorganic processes.

Mischmetal

An alloy of rare earth metals containing about 50% lanthanum, neodymium, and similar elements.

Miscibility

Solubility; ability of two or more liquids to form a homogeneous solution.

Misrun

Denotes an irregularity of the casting surface caused by incomplete filling of the mold due to low pouring temperature, gas back-pressure from inadequate venting of the mod, and inadequate gating.

Mitis Casting

Casting of very mold steel.

Mock-Up

A full-size model built accurately for study, testing or display.

Model

A proportional representation of an object in any scale.

Modell Number

A value giving a measure of wear resistance.

Modification

A process in which the eutectic temperature, structure, and composition of aluminum-silicon alloys are apparently altered by the addition of small amounts of a third element, such as sodium. A similar phenomenon can be effected by chill casting.

Modulus Of Elasticity (E)

In tension it is the ration of stress to the corresponding strain within the limit of elasticity (Yield Point) of a material. For carbon and low alloy steels any composition and treatment, the value is approximately 30,000,000 psi.

Modulus of Resilience (ur)

The amount of strain energy per unit volume required to stress a material from zero to the yield stress limit. The modulus of resilience is proportional to the area under the elastic portion of the stress-strain diagram. Units are Pa or psi.

Modulus of Rigidity

In a torsion test the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range.
See Shear Modulus

Modulus of Rupture

Used in both bending and torsion testing. In bending, the modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus.

Modulus of Toughness (ut)

Amount of work per unit volume of a material required to carry that material to failure under static loading. Equal to the area under the entire stress-strain curve. Units are Pa or psi.

Mogullizer

Equipment for sealing by vacuum impregnation of small pores in castings.

Moh's Scale

A scratch hardness test for determining comparative harness using ten standard minerals, from talc to diamond.

Moisture Content

The amount of water contained in a substance that can be driven off by heating at 220 - 230°F (104.4 - 110°C).

Moisture Teller

A patented apparatus for the rapid determination of moisture content of molding sand.

Mosture, Workable

That range of moisture content within which sand fills, rams, draws, and dries to a satisfactory mold, and within which the sand does not dry out too fast to mold and patch.

Molasses Water

A solution of water and molasses sprayed on sand molds to strengthen mold surface and yield a fine finish layer.

Mold Blower

Molding equipment for blowing sand mixture onto the pattern with compressed air; allows for faster production than gravity rollover dump.

Mold Board (Follow Board)

The board upon which the pattern is placed to make the mold.

Mold Cavity

The space in a mold which is filled with liquid metal to form the casting upon solidification. The channels through which liquid metal enters the mold cavity (sprue, runner, gates) and reservoirs for liquid metal (risers) are not considered part of the mold cavity proper.

Mold Clamp

Devices used to hold or lock cope and drag flask parts together.

Mold Coating (Mold Facing, Dressing)

1) Coating to prevent surface defects on permanent mold castings and die castings, 2) coating on sand molds to prevent metal penetration and improve metal finish.

Mold Cover Half (Cover Die)

1) The top half of the mold, the cope, 2) in die casting, the front half of the die, which remains stationary as the die is opened.

Mold Facing

See Mold Coating

Mold Jacket

A wooden or metal form slipped over a mold to support the side during pouring.

Mold Shift

A casting discontinuity resulting from misalignment of the cope and drag halves.

Moldability

Ability of sand to flow into a flask and around a pattern; measured in the amount of sand falling through an inclined screen or slot.

Moldabilty Controller

A patented device for controlling water additions to sand mix to maintain a consistent moldability index.

Molding, Bench

Making sand molds by hand tamping loose or production patterns at a bench without assistance of air or hydraulic action.

Molding, Floor

Making sand molds from loose or production patterns of such size that they cannot be satisfactorily handled on a bench or molding machine, the equipment being located on the floor during the entire operation of making the mold.

Molding Gravel

The coarser and more permeable grades of molding sand generally used in production casting of exceptional size and weight.

Molding Material

A material suitable for making molds into which molten metal can be cast.

Molding, Pit

Molding method in which the drag is made in a pit or hole in the floor.

Molding Sand Mixture

A sand mixture suitable for making molds into which molten metal can be cast.

Molding Sands

Sands containing over 5% natural clay, usually between 8 and 20%.
See also Naturally Bonded Molding Sand

Molecular Weight

Weight of the smallest quantity of a substance processing all its normal physical properties.

Molecule

The smallest particle of a substance that can exist in the free state and which has the same composition as any larger mass of the substance.

Molybdenum

A metal used widely in alloying of other metals. It is used as hardening element for steel, and for diecasting dies. Melting point 2620°C (4748°F), atomic number 42.

Molybdic Oxide

The oxide of molybdenum; added to the furnace in briquetted form as an important finishing constituent in nitriding steels.

Monel

A high nickel alloy, approximately 67% Ni, 28% Cu, the balance Fe, Mn, Si and other elements. Monel metal is resistant to corrosion and is widely used to resist the action of acids.

Monitoring

1) Periodic or continuous determination of the does rate in an occupied area (area monitoring) or the does received by a person (personnel monitoring), 2) periodic or continuous determination of the amount of ionizing radiation or radioactive contamination present in an occupied region, as a safety measure for purposes of health protection, 3) personnel - monitoring any part of any individual, his breath, or excretions, or any part of his clothing.

Monitoring Area

Routine monitoring of the level of radiation or of radioactive contamination of any particular area, building, room or equipment. Usage in some laboratories or operation distinguishes between routine monitoring and survey activities.

Monkey Cooler (Brit.)

In a blast furnace, the smaller of a series of three water coolers protecting the cinder notch. The largest is the cooler, while the in-between cooler is the intermediate cooler.

Monocast Process

A patented application of resin-bonded sand to line the flask in the production of centrifugal cast pipe. The resin-bonded layer is thinner than the conventional sand lining.

Monotectic

An isothermal reversible reaction in a binary system, in which a liquid on cooling, decomposes into a solid and a second liquid of different composition.
(Compare with Eutectic.)

Monotron

An instrument for measuring indentation hardness. It is fitted with two dials, one to measure depth of penetration, the other the load.

Montmorillonite

A very plastic clay, more siliceous than kaolinite; the principal constituent of bentonite.

Moore, R. R., Fatigue Machine

A constant load rotating bending type fatigue testing machine.

Mother Metal

The molten alloy just before final solidification and freezing out of the solid.

Motorized Variac

An autotransformer for stepless voltage control in shell molding.

Mottled Cast Iron

Iron which consists of a mixture of variable proportions of gray iron and white cast iron; such a material has a mottled fracture.

MP

Melting point.

Ms

The temperature at which transformation of austenite to martensite starts during cooling.

Mud

A term frequently used to designate plastic lining materials.
See also Daubing

Mud Daub

See Daubing

Muffle Furnace (Kiln)

A furnace in which the heating is indirect; the material to be heated is contained in a refractory container heated from the outside.

Muller

A type of foundry sand-mixing machine.

Mulling and Tempering

The thorough mixing of sand with a binder, either natural or added, with lubricant of other fluid, as water.

Muliductor Power Source

A device to convert standard 3-phase, 60 cycle current to single- phase, 180-cycle current, so-called medium frequency; produces a strong, controlled stirring action for induction melting.

Multiple Mold

A composite mold made up of stacked sections, each of which produces a complete gate of castings, and poured from a central downgate.

Mushet Steel

An air hardened steel containing about 2% c, 2% Mn, and 7% W, developed by Scotsman Robert Mushet in 1870.

Mushy Stage

The state between sold and liquid in alloys which freeze over a wide range of temperatures.

NACE

National Association of Corrosion Engineers

NBS

Formerly National Bureau of Standards, now National Institute of Standards and Technology

NISA

National Industrial Sand Association

National Machine Tool Builders Association

Association for Manufacturing Technology

Natural Aging

See Aging

Natural Sand

Unconsolidated sand, sand derived from a rock in which grains separate along their natural boundaries. This includes soft sandstone where little pressure is required to separate the individual grains.

Naturally Bonded Molding Sand

A sand containing sufficient bonding material as mined to be suitable for molding purposes. Seldom used today in the metalcasing industry.

Navy (USA) Tear Test

A method of evaluating the susceptibility of ship plate to brittle or cleavage type fracture.

NDDT

Nil ductility transition temperature, determined in the dropweight test. Refers to the absence of the ductile fracture appearance and any reduction in area due to the brittle behavior of the steel.

Neat Brick

Brick with faces arranged so one of the flat faces in inclined toward the other, almost eliminating one end face.

Neat Cement

Portland Cement mixed with water only.

Neck Down (Knock-Off, Wafer Core, Washburn, Cameron Core)

A thin core or tile used to restrict the riser neck, making it easier to break or cut off the riser from the casting.
See Core

Necking

Reducing the cross sectional area of the metal in an area by stretching.

Necking Down

Reduction in area concentrated at the subsequent location of fracture when a ductile metal is stressed beyond it yield point in tension.

Needles

Elongated acicular crystals, tapering at each end to a fine point, as martensite.

Needling Agents

Special agents such a boron which markedly increase the hardness of steel.

Negative Quenching (Negative Hardening)

Accelerated cooling in water or oil, from a temperature below the critical range.

Negative Thermoie Heat Exchange

In shell molding, improving the mass-surface ratio by simulating profile geometry of pattern or core cavity on the underside; will boost running temperature of high projections by 25 percent.

Nesh (Hot Short)

A British term applied to metal that is weak and ruptures easily under not working conditions.

Network Structure

A structure in which the grains or crystals of one constituent are partly or entirely enveloped in another constituent; an etched section through the crystals resembles a network.

Neumann Band

A mechanical twin in ferrite.

Neutral Refractories

A loose term designating refractories which presumably will not react with so-call acid or basic refractories and slags.

Neutron

Elementary nuclear particle with a mass (1.00893 mass units) approximately the same as that of a hydrogen atom. It is electrically neutral.

New Jersey Sand

A large number of grades of foundry sands mined in southern New Jersey.

NFFS

Non-Ferrous Founder's Society

Nichrome

Oxidation-resistant alloy 65% Ni, 20% Fe, and 15% Cr.

Nickel

Element used for alloying iron and steel as well as nonferrous metals; melting point 1455°C (2651°F). Nickel is also a base metal for many casting alloys resistant to corrosion and high temperature oxidation.
See Monel, Nimonic, Inconel, Ni-Hard

Ni-Hard

Hard white cast iron containing 4% Ni and 2% Cr.

Nimonic

Class of nickel-base cast alloy resistant to stress and to oxidation at high temperatures.
See Inconel

Nine-Inch Equivalent

Standard unit of volume in refractories industries; 9x4-1/2,2-1/2 in brick.

Nipple

A pipe coupling consisting of a short piece of threaded tubing.

Nital

A solution of nitric acid in alcohol use as an etching agent in ferrous metallography.

Nitriding

A surface hardening process involving heating in a atmosphere of ammonia or in contact with a nitrogen-bearing material so as to promote the absorption of nitrogen.

Nitrogen Flush

Bubbling nitrogen gas through a metal melt under vacuum (as with valve bronze) to improve tensile properties and pressure tightness.

Nobake Binder

A synthetic liquid resin sand binder that hardens completely at room temperature, generally not requiring baking, used in Cold-Setting process.

Noble Metals

Metallic elements with surfaces that do not readily oxidize in air; e.g., gold, silver, platinum.

Nodular Fireclay (Burley, Burley Flint)

Rock containing aluminous or ferrogenous nodules, or both, bonded by fireclay.

Nodular Graphite

Graphite or carbon in modular form, characteristically in malleable and nodular iron.

Nodular Iron

Iron of a normally gray cast iron type that has been suitably treated with a nodularizing agent so that all or the major portion of its graphitic carbon has a nodular or spherulitic form as cast. Often referred to as Ductile Iron.

Noise Radiator

A device creating noise.

Noise Spectrum

The various frequencies making a noise.

Nomogram (Graph)

A graph that enables one by the aid of a straight-edge to read off the value of a dependent variable when the value of two or more independent variables are given.

Nondestructive Testing (Inspection)

Testing or inspection that does not destroy the object being tested or inspected.

Nonferrous

A negative term, refers to alloy in which the predominate metal or solvent is not iron.

Non-Ferrous Founders' Society

Non-Ferrous Founder's Society

Normal Segregation

Concentration of alloying constituents that have low melting points in those portions of a casting that solidify last.

Normal Steel

Steel in which the pearlite is completely laminated.

Normalizing

Heating a ferrous alloy to a suitable temperature above the transformation temperature Ac3, followed by cooling at a suitable rate, usually in still air to a temperature substantially below the transformation range.

Notch Bar

Small size ingot with notches to facilitate breakage for remelting.

Notched Bar

A test specimen which is notched. Used in impact or fatigue tests.

Novalak

A two-step basic flake resin with no thermosetting properties, applied to sand in shell molding process as a mold or solution.

Nozzle

Pouring spout of the bottom-pour ladle.

Nozzle Brick

A thick-walled tubular refractory shape set in bottom of a ladle through which steel is teemed.

Nozzle Pocket Brick

A refractory shape set in bottom of a ladle containing a recess in which nozzle is set.

NTP

Normal temperature and pressure reference point; zero centigrade 760mm mercury pressure.

Nucleation

1) (homogeneous) the initiation of solid crystals from the liquid stage, or initiation of solid crystals from the liquid stage, or a new phase within a solid without outside interference - rarely occurs, 2) heterogeneous) foreign particles altering the liquid-solid interface energy during phase changes.

Nucleus

The first structurally determinate particle of a new phase or structure that may be about to form. Applicable in particular to solidification, recrystallization, and transformations, in the solid state.

Oddsides

Semi-permanent molds of plaster of paris, graphite, or dry sand, tarred and dried and used for repetitive work in the foundry.

Off-Dimension

A casting defect caused by any incorrect dimension resulting from improper setting of cores, using wrong core, shifts, swells, etc.

Off-Gage (Off-Size)

Core defect caused by improper gagging of dimensions.

Off-Grade Metal

Metal whose composition does not correspond to the designated or applicable specification.

Off Iron

Pig iron not of the desired composition.

Oil and Whiting Test

A method of detecting fine cracks by applying a penetrating oil and painting the tested metal surface with a mixture of whiting and a thinner. Oil in the cracks emerges to stain the whiting.

Oil Core or Mold

A core or mold in which the sand is bonded by an oil binder.

Oil-Oxygen Binder (Cold-Setting, Air-Setting Binders)

A synthetic auto-oxidizing liquid, oil-based binder that partially hardens at room temperature, using an oxygen releasing agent. Baking is needed to complete the hardening

Oil Quenching

Quenching in oil.
See Quenching

Oil Sands

Sand bonded with such oils as linseed and the synthetics.

Oil Shot

In die casting, a sponge like whirl on the surface of casting resulting from an excess of oil applied to the sprue hole before the shot was made.

Olive

(Mg2,Fe2SiO4) A naturally occurring mineral composed of fosterite and fayalite, crushed and used as a molding sand. Usually the sand of choice in manganese steel casting due to its basicity.

One-Piece Pattern

Solid pattern, not necessarily made from one piece of material. May have one or more loose pieces.

One-Screen

A distribution of a clean sand or a sand with two maximum screens separated by a minimum screen. These high-expansion problem sands are also referred to as camel back distributions.

Open Face Mold

See Open Sand Casting

Open Flame Furnace

As opposed to the crucible furnace; in the open-flame furnace the metal charge is confined in the refractory lining, with the flame and products of combustion coming in direct contact with the metal.

Open Grain Structure

A defect wherein a casting, when machined or fractured, appears to be coarse grained and porous; usually due to a shrink area.

Openhearth Furnace

A furnace for melting metal, in which the bath is heated by the combustion of hot gases over the surface of the metal and by radiation from the roof.

Open Riser

See Riser, Open

Open Sand Casting

A casting produced in an open mold; poured in the drag, with no cope or other top covering.

Optical Pyrometer

A temperature measuring device through which the observer sights the heated object and compares its incandescence with that of an electrically heated filament whose brightness can be regulated; or the intensity of the light admitted from the object may be varied through filters and compared with a constant light source.

Optimum Moisture

That moisture content which results in developing the maximum of any property of a sand mixture.

Orange Peel

A pebble-grained surface that develops in the mechanical forming of sheet metals with coarse grains.

Orange Peel Bucket

A bottom-drop bucket used for charging cupolas; the drop-bottom is divided into a number of sections that appear to peel back as the bucket opens.

Ore

A mineral from which a metallic element may be extracted profitably.

Oriffice

An opening of controlled size used to measure or control the flow of gases.

Oriffice Plate

In a cupola a device used to measure the volume of air delivered to the windbox.

Osmondite

An obsolete term once used to designate a ferrous microstructure not so well defined as Troosite.

Oscillating Trough Cooler

A steel trough conveyor within a plenum where reclaimed sand is cooled prior to reuse.

Ottowa Sand

A sand originating near Ottawa Ill., also know as St. Peter sandstone.

Oven, Drying

A furnace or oven for drying molds or cores.

Ovens

See Continuous Annealing Furnace

Overaging

Aging a precipitation-hardening alloy under conditions of time and temperature greater than those required to obtain maximum strength or hardness.

Overfiring

Heating refractories to a temperature sufficient to cause pronounced vitrification, deformation, or bloating.

Overflows (Overflow Wells)

Separated cavities cut into the face of die casting dies adjacent to the main cavity and connected to it by a channel, ensuring filling of cavity.

Overhand

Extension of the end surface of the cope half of a core print beyond that of the drag to provide clearance for closing of the mold.

Overheated

A term applied when, after exposure to an excessively high temperature, a metal develops an undesirable coarse grain structure, but is not necessarily damaged permanently. Unlike burned structure, the structure produced by overheating can be corrected by suitable heat treatment, by mechanical work, or by a combination of the two.

Overstressing

Permanently deforming a metal by subjecting it to stresses that exceed the elastic limit.

Owen Jet Dust Counter

An instrument similar to the Konimeter, using the humidification factor.

Oxidation

Any reaction of an element with oxygen. In a narrow sense, oxidation means the taking on of oxygen by an element or compound, and on the basis of the electron theory it is a process in which an element loses electrons.

Oxidation Losses

Reduction in amount of metal or alloy through oxidation. Such losses usually are the largest factor in melting loss.

Oxide

A compound of oxygen with another element.

Oxidizing Atmosphere

An atmosphere resulting from the combustion of fuels in an atmosphere where excess oxygen is present, and with no unburned fuel lost in the products of combustion.

Oxygen Bomb Calorimeter

An instrument to measure the heats of combustion of solid and liquid fuels.

Oxygen Impingement Process

Pure oxygen is blown down on the bath to refine pig iron.

Oxygen Lance

See Lance, Oxygen

P1

In production, the acceptable quality level.

P2

In production, lot tolerance.

Pack Hardening (Park Carburizing)

See Case Harding

Packing or Packing Material

Sand, gravel, mill scale or similar materials used to support castings packed in annealing pots, to prevent possible warpage under high temperatures.

Padding

The process of adding metal to a cross section of a casting wall, usually extending from a riser, to ensure adequate feed to a localized area where a shrink would occur if the added metal were not present.

Panel Spalling Test

A test using a panel of the refractory being tested to provide a reference to spalling behavior.

Panoramic Analyzer

An instrument for analyzing sounds and displaying the results either on an oscilloscope or a graph.

Parkerizing

A proprietary method of producing a protective phosphate coating on ferrous metals. Parker A treatment involves immersing in a bath of acid manganese phosphate. The Parker D is a modification using acid zinc phosphate with a nitrate iron as accelerator.

Parlanti Casting Process

A proprietary permanent mold process using dies of aluminum with a controlled rate of heat transfer.

Parsons Duncan Process

A method of casting steel ingots wherein the top layer of the mold is heated and the last to solidify.

Parted Pattern

A pattern made in two or more parts.

Partially Graphitized Cast Iron

A blackheart malleable casting only partly graphitized in annealing, giving a mixture of black and white. Sometimes termed salt and pepper fracture.

Particulate Matter

In air pollution control, solid or liquid particles, except water, visible with or without a microscope, that make up the obvious portion smoke.

Parting Agent

See Release Agent

Parting Line

A line on a pattern or casting corresponding to the separation between the cope and drag portions of a sand mold.

Passivator

An inhibitor which changes the potential of a metal to a more cathodic value.

Passivity

The property of some metals to become abnormally inactive towards certain reagents.

Patching

Repair of a furnace lining; repair of a mold core.

Pattern

A form of wood, plastic, metal, or other material around which molding material is placed to make a mold.

Pattern Draft

The taper on vertical elements in a pattern which allows easy separation of pattern from compacted sand mixture.

Pattern Layout

Full-sized drawing of a pattern showing its arrangement and structure features.

Patternmaker

A craftsman engaged in production of foundry patterns from wood, plastic, or metals, such as aluminum, brass, etc.

PCE

Pyrometric Cone Equivalent

Pearlite

A lamella aggregate of ferrite and carbide, the structure of pearlite can appear fine or coarse depending on processing.

Peen

Peening action obtained by impact of metal shot, often used to improve fatigue properties by putting the surface in compression.

Pencil Core

A core projecting to the center of a blind riser allowing atmospheric pressure to force out feed metal.

Penetrameter

A strip of metal with stepped thickness variation and with holes at varying depths; used in radiography to indicate the sensitivity of the radiograph.

Penetration, Metal

Condition where molten metal has penetrated into the sand, resulting in a mixture of metal and sand adhering to the casting.

Periclase

Natural magnesia in nodular form, formed by heating.

Perlite

A highly siliceous volcanic rock which can be expended by heating into a porous mass of particles. Perlite can be used as an insulation in foundry sand mixtures. Not to be confused with Pearlite.

Permanent Mold

A metal mold of two or more parts; not an ingot mold. It is used repeatedly for the production of many casting of the same form.

pH

A symbol denoting the negative logarithm of the concentration of the hydrogen ion in gram-atoms per liter, used in expressing both acidity and alkalinity; pH=log 1/H per liter. An important factor in foundry sand control, pH7 is neutral; values less than 7 acid, and higher than 7, basic.

Phase Diagram

A graphic representation of the equilibrium temperature and composition limits of phase fields reactions in an alloy system. In a binary system, temperature is usually the ordinate and composition the abscissa. Ternary and more complex systems require several two-dimensional diagrams to show the temperature - composition variables completely. In alloy systems, pressure is usually considered constant, although it may be treated as an additional variable.

Phenolic Resin (One-Step)

A resin made by the polymerization of a phenol with an aldehyde; used a binder for cores and sand molds.
See Urea-Form-aldehyde Resin

Photomicrograph

A photograph of the grain structure of a metal as observed when optically magnified more than 10 diameters. The term micrograph may be used.

Physical Metallurgy

The science concerned with the physical and mechanical characteristics of metals and alloys.

Physical Properties

For definitions of specific physical properties see

Picral

An etchant for ferrous alloys; 4% picric acid in alcohol.

Pig Iron, Basic

A grade of iron made from the basic open-hearth process of steelmaking; P, 0.40% max. for Northern iron, 0.70 to 0.90% for Southern iron; S 0.05% max. and Si, 1.50%.

Pig Iron, Chateaugay

Pig iron from Chateaugay (New York State) ores very low in phosphorus; copper-free and containing appreciable amounts of titanium.

Pilot Casting

Casting produced prior to the production run to verify correctness of procedures, materials, and process to be used in production.

Pipe

A cavity formed by shrinkage of the metal during solidification, usually occurring in a riser having feeder metal for the casting.

Pitting

A form of wear characterized by the presence of surface cavities, the formation of which is attributed to processes such as fatigue, local adhesion, cavitation or corrosion.

Plaster of Paris

A semi-hydrated form of calcium sulfate made by sintering gypsum to 120 - 130C (248 - 266F).

Plane Strain

A stress condition in linear elastic fracture mechanics (See LEFM) in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth. Under plane strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress.

Plasma Refining

Process used to reduce sulfur and oxygen to very low levels.

Plastic Deformation

Permanent distortion of a material under the action of applied pressure.

Plates, Core Drying

Flat plates of metal on which cores are placed for baking.

PMMA

Polymethymethacralate - Foam used in the lost foam process, does release as much carbon as polystyrene.

Pohland Method

A technique for the ultrasonic testing of steel in which a visible image of the defects present in the steel can be shown on a screen.

Polystyrene

A polymer of styrene used in making molding products. In particular, used in the lost foam process.

Postheating

A process used immediately after welding whereby heat is applied to the weld zone either for tempering or for providing a controlled rate of cooling, in order to avoid a hard or brittle structure.

Pouring

Transfer of molten metal from furnace to ladle, ladle to ladle, or ladle into molds.

Pouring Cup

The flared section of the top of the downsprue. It can be shaped by hand in the cope, or be a shaped part of the pattern used to form the downsprue; or may be baked core cup placed on the top of the cope over the downsprue.

Powder Cutting

Introducing iron powder in an oxygen stream to hasten oxygen torch cutting by the combination of fluxing and oxidation. Generally used for cutting stainless steel.

Precipitation Hardening

A process of hardening an alloy in which a constituent precipitates from a supersaturated solid solution.

Precipition Heat Treatment

Any of the various aging treatments conducted at elevated temperatures to improve certain mechanical properties through precipitation from solid solution.

Preheating

A general term for heating material, as a die in die casting, as a preliminary to operation, to reduce thermal shock and prevent adherence of molten metal.

Pressure Die Casting

A British term.
See Die Casting

Pressure-Tight

A term describing a casting free from porosity of the type that would permit leaking.

Primary Choke (Choke)

That part of the gating system which most restricts or regulates the flow of metal into the mold cavity.

Primary Crystals

The first dendritic crystal that form in an alloy during cooling below the liquidus temperature.

Process Capability

The amount of variation in the output of a controlled manufacturing process, the range defined by plus or minus three standard deviations.

Product Analysis

In castings, the analysis of the actual part as opposed to the analysis of the steel from which the casting was poured.

Production Welding

Any welding carried out during manufacturing before final delivery to the purchaser. This includes joint welding of casting and finishing welding.

Proeutectoid

The constituent that separates out of a solid solution before the formation of eutectoid.

Profile Tolerances

A system of locating and tolerancing developed to control the orientation of rough parts in machine fixtures. From locating points on the casting a " perfect profile " is established for all surfaces and features. A tolerance envelope surrounding that profile defines the limitations of an acceptable part.

Protection Tube

A metal, graphite, or ceramic tube which shrouds and protects the wires of a thermoelectric pyrometer.

psi

Pounds per square inch.

Pugnill

A mill for mixing foundry sands and sand mixtures consisting essential of a shaft fitted with plows or paddle wheel which revolve in a tub or vat.

Punchout Machines

A machine used to force the entire sand and casting contents from the molding box in one motion, without the use of vibration.

Purging

Elimination of air and other undesirable gases from furnaces or heating boxes.

Pyrometallurgy

Chemical metallurgical process dependent upon heat.

Pyrometric Cone

A slender trihedral pyramid made of a mixture of minerals similar in composition to that of a clay or other refractory being tested. Each cone is assigned a number indicating its fusion temperature.

Pyrometric Cone Equivalent (PCE)

An index of refractoriness obtained by heating on a time-temperature schedule a cone of the sample material and a series of standardized pyrometric cones of increasing refractoriness.

Pyrometry

A method of measuring temperature with any type of temperature indicating instruments.

Quartz

A form of silica occurring in hexagonal crystals which are commonly colorless and transparent, but sometimes also yellow, brown, purple, green, etc. It is the most common of all solid minerals.
See also Silica

Quartzite

A compact granular rock composed of quartz. It is a metamorphosed sandstone, and siliceous cement is often so blended with the quartz grains as to give the rock a nearly homogeneous texture. Primary materiel in silica brick.

Quench Crack

A crack resulting from thermal stress induced during rapid cooling or quenching, or from stresses induced by delayed transformations some time after the article has been fully quenched.

Quench Severity

The quench severity is characterized by the H value and relates to the rate of temperature change during quenching.

Quenching

Rapid cooling of hardening; normally achieved by immersion of the object to be hardened in water, oil, or solutions of salt or organic compounds in water.

Radiant Heat

Heat communicated by radiation and transmitted by electromagnetic waves.

Radiation Area

Any part of an installation accessible to employees in which there exists a radiation level of 7.5 millirem in any one hour over 150 millirem in any seven consecutive days.

Radiation, Direct

All radiation coming from within an x-ray tube and tube housing except the useful beam.

Radiation Hazard

Any situation where persons might be exposed to radiation in excess of the maximum permissible dose.

Radioactive Isotopes

Varieties of an element possessing the same chemical characteristics but emitting detectable radiation's by means of which they can be identified and traced.

Radioactive Material

Any compound or element which may emit any or all of the following: alpha and beta particles, electrons, photons neutrons and gamma and all other emissions which produce ionization directly or indirectly.

Radium

A radioactive element which the chemical symbol Ra; radium and its salts are used in gamma-ray radiography because of their radioactivity. Melting point is 700°C (1292°F).

Ramming

Packing sand in a mold by raising and dropping the sand, pattern, flask on a table. Jolt squeezers, jarring machines, and jolt rammers are machines using this principle.

Range

The difference between the highest and lowest values of a measurable attribute of the output of a process.

Rapping

Knocking or jarring the pattern to loosen it from the sand in the mold before withdrawing the pattern.

Papping Plate

A metal plate attached to a pattern to prevent injury to the pattern and assist in loosening it from the sand.

Rare Earth (RE)

Any of a group of 15 similar metals with atomic numbers 57 to 71. Also rare earth element, rare earth metal, lanthanide series, uncommon metals, Mischmetal.

Rare Gases

Helium, argon, neon, krypton, xenon and radon.

Rat Tail

An expansion discontinuity in a sand casting, featured as a long, narrow, linear depression, resulting from sand expansion and minor buckling of the mold surface during filling of the mold.

Receiving Ladle

A ladle placed in front of the cupola into which all metal is tapped. It acts as a mixer and reservoir and to smooth out metal flow to the pouring area.

Recrystallization

A process whereby the distorted grain structure of cold-worked metals is replaced by a new, strain-free grain structure during annealing above a specific minimum temperature.

Recrystallization Temperature

The lowest temperature at which the distorted grain structure of a cold-worked metal is replaced by a new, strain-free grain structure during prolonged annealing. Time, purity of the metal, and prior deformation are important factors.

Reduction

The removal of oxygen or addition of hydrogen.

Reflectoscope

An instrument for the ultrasonic testing of metals.

Refractory

1) Heat-resistant material, usually non-metallic, used for furnace linings etc., 2) the quality of resisting heat.

Refractory Clay

A clay which fuses at pce 25 (1590C, 2894F) or higher.

Regression Analysis

A statistical method of determining, or predicting, the value of a dependent variable, based on levels of one or more know independent variables.

Release Agent (Parting Agent)

A material, e.g. silicone, stearate, oil, or wax for lubricating a die pattern or core box to facilitate easy removal of a casting, mold or core.

Remanence

The remaining flux density after the magnetizing force has been removed.

Remelt

See Revert

Repair Welding

Any welding carried out after delivery to the end user, i.e., after the casting has been in service.

Replicast Process (CS)

A ceramic shell process similar to the investment casting process. Uses a pattern made from expanded polystyrene (EPS) and is surrounded by a thin ceramic shell.

Residual

Any element remaining in any alloy following melting and casting which was not added to meet an analytical specification limit.

Residual Stress

See Stress, Residual

Resolved Shear Stress

Stress operating on a crystallographic slip system.

Respirator

A filtering device which covers the nose and mouth and prevents inhalation of dust or fumes; should have the U.S. Bureau of Mines certificate or approval for the specific contaminant being filtered out. Handkerchiefs and gauze masks give little or no protection.

Revert

Recycled sprues, gates, risers, defective castings and machine chips.

Reynolds Numbers

Used in hydraulics and in casting gating theory. A dimensionless value (dynamic viscosity / density) describing the fairly sudden shift of flow from laminar to turbulent. Re > 2000 represents turbulent flow. Laminar flow is seldom experienced in runner and gating systems.

Rigging

Gates, risers, loose pieces, etc., needed on the pattern to produce a sound casting.

Rimmed Steel

A low-carbon steel.

Ringelmann's Scale

In air pollution control, a black and white mesh scale reading from all clear to solid black, used to measure the density of smoke. Observer normally uses chart comparator 50 feet from the point where smoke emits.

Riser

Reservoir of molten metal from which casting feeds as it shrinks during solidification.

Riser, Blind

A riser that does not break through the top of the cope and is entirely surrounded by sand; opened to the atmosphere by means of a firecracker core.

Riser Distance

The length of the riser neck. The term is applied to side risers only.

Riser-Gating

Practice of running metal for the casting through the riser to help directional solidification.

Riser Height

The distance from the top of the riser when liquid to the top of the riser neck. Riser height when sold is usually several inches less than when liquid because of contraction and loss of feed metal to the casting.

Riser Neck

The connecting passage between the riser and casting. Usually only the height and width or diameter of the riser neck are reported, although the shape can be equally important.

Riser, Open

Conventional form of riser usually located at the heaviest section of the casting and extending through the entire height of the cope.

Riser Pad (Riser Contact)

An enlargement of the riser neck where it joins the casting. The purpose of the pad is to prevent the riser from breaking into the casting when it is struck or cut from the casting.

Riser, Side (Side Head)

A riser attached to the side of a casting.

Riser, Top (Top Head)

A riser attached to the top surface of a casting.

Rockwell Hardness

See Hardness

Rodding

Reinforcing the sand in a core with metal rods or shapes to strengthen parts of the core.

Rolling Over

The operation of reversing the position of a flask. If the drag part of the pattern has been rammed with the parting surface downward, it is rolled over 180 degrees to allow core setting and placement of cope.

Rollover Board

A wood or metal plate on which the pattern is laid top face downward for ramming the drag half mold, the plate and half mold being turned over together before the joint is made.

Rollover Machine

A molding machine with which the flask is rolled over before the pattern is drawn from the mold.

Runner

A channel through which molten metal or slag is passed from one receptacle to another; in a mold, the portion of the gate assembly that connects the downgate or sprue with the casting ingate or riser. The term also applies to similar portions of master patterns, pattern dies, patterns, investment molds and finished castings.

Runner Extension

In a mold, that part of a runner which extends beyond the farthest ingate as a blind end. It acts as a dirt trap since the first rush of metal along the runner will pick up any loose particles of sand or dirt and carry them into the extension and not into the mold cavity.

Runner Riser

A conventional runner, usually in the horizontal plane, which permits flow of molten metal to the ingate and is large enough to act as a reservoir to feed the casting.

Runout

A casting defect caused by incomplete filling of the mold due to molten metal draining or leaking out of some part of the mold cavity during pouring; escape of molten metal from a furnace, mold or melting crucible.

SAE Specifications

A set of materials specification issued by the Society of Automotive Engineers, Inc.

Sag

A decrease in metal section in casting due to sagging of the cope or core.

Salamander

1) A heating device, usually of drum shape, in which fuel is burned in the open air by natural draft, 2) iron which has collected in the bottom of a blast furnace during a blow.

Salt Bath

A bath of molten salts used for heating steels, for hardening or tempering.

Sand

In metalcasting, a loose, granular material high in SiO2, resulting from the disintegration of rock. The name sand refers to the size of grain and not to mineral composition. Diameter of the individual grains can vary from approximately 6 to 270 mesh. Most foundry sands are made up principally of the mineral quartz (silica). Reason for this is that sand is plentiful, refractory, and cheap; miscellaneous sands include zircon, olivine, chromite, CaCO3, black sand (lava grains), titanium minerals and others.

Sand Casting

Metal castings produced in sand molds.

Sand Control

Procedure whereby various properties of foundry sand, such as fineness, permeability, green strength, moisture content, etc., are adjusted to obtain castings free from blows, scabs, veins, and similar defects.

Sand Mulling

A method of evenly distributing the bond around the sand grain by a rubbing action.

Sand Plow

A bladed device used to divert sand from a belt conveyor into a sand hopper.

Sand Porosity

Volume of the pore spaces or folds in a sand. (Not synonymous with permeability).

Sand Reclamation

Processing of used foundry sand grains by thermal, attraction or hydraulic methods so that it may be used in place of new sand without substantially changing current foundry sand practice.

Sand Tempering

Dampening and cutting over or otherwise mixing sand to produce uniform distribution of moisture, and allowing time for migration of water molecules.

Sand Wall

Temporary independent wall separated from a slag pocket wall; facilitates slag removal and protects permanent wall.

Scab

An expansion discontinuity defect on the surface of a casting which appears as a rough, slightly raised surface blemish, crusted over by a thin porous layer of metal under which is a honeycomb or cavity that usually contains a layer of sand.

Scaling (Scale)

Surface oxidation, partially adherent layers of corrosion products, left on metals by heating or casting in air or in other oxidizing atmospheres.

Scanning Electron Microscope (SEM)

An instrument used for obtaining microstructure images using an electron beam. The micrographs obtained give depth perception of the metal being observed.

Scarfing

Cutting off surface projections such as gates and risers from casting by means of gas torch.

Scrap (Metal)

Metal to be remelted; includes scrapped machinery fabricated items such as rail or structural steel and rejected castings.

Screen Analysis (Sieve Analysis)

Distribution of particle size sand expressed in terms of the percentage of weight retained on each of a series of standard screens decreasing in mesh size and the percentage passed by the screen of finest mesh.

Screen (Sand)

A sieve or riddle with openings of definite size used to separate one gain size from another or to remove lumps from sand.

Scrubbers

See Wet Scrubbers

Sealed Source

Any radioactive material that is encased in and is to be used in a container in a manner intended to prevent leakage of the radioactive material.

Seam

A surface defect on a casting related to but of lesser degree than a Cold Shut; a ridge on the surface of a casting caused by a crack in the mold face.

Segregation

A concentration of alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid.

Selenium

A metalloid melting 220°C (428°F) added to stainless steel to improve machinability.

Separator

A mechanical unit which separates or grades ground materials into constituent parts, used in the foundry to remove fines from the system sand and dust from the air.

SFSA

That's us.

Shakeout

1) The operation of removing castings from the mold 2) a mechanical unit for separating the molding materials from the solidified metal casting.

Shank

The handle attached to a ladle.

Shaw (Osborn-Shaw) Process

A precision casting technique in ceramic molds which do not require wax or plastic investment.

Shear

A type of deformation in which parallel planes in the metal crystals slide so as to retain their parallel relation.

Shear Modulus (G)

In a torsion test, the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range. Units are Pa or psi.

Shear Strain

Elastic displacement produced by pure shear loading.

Shear Strength

Maximum shear stress a material is capable of withstanding without failure.

Shear Stress

Load per unit area parallel to the plane of contact.

Shell Molding

A process for forming a mold from resin-bonded sand mixtures brought in contact with pre-heated (300-500°F) metal patterns, resulting in a firm shell with a cavity corresponding to the outline of the pattern.

Shift

A casting defect caused by mismatch of cope and drag or of cores and mold.

Shortness (Hot)

Brittleness in a metal at an elevated temperature.

Shotbalsting (Shot Peening)

Casting cleaning process employing a metal abrasive (grit or shot) propelled by centrifugal or air force.

Shrink

The difference in volume between liquid metal and solid metal or the void (shrink hole) left in a casting because of it.

Shrinkage

1) Liquid, contraction in volume as metal cools to solidification, 2) solidification, contraction in volume when the metal passes from the liquid to the sold at the freezing point (may expend over a range), 3) solid, the contraction on cooling from freezing point to normal temperature, 4) the decrease in dimension in clays occurring when drying at 100°C (212°F) and even more so on firing, 5) reduction in dimension of refractory material during heating.

Shrinkage Cracks

Cracks that form in metal as result of the pulling apart of grains by contraction before complete solidification.

Shrinkage, Patternmakers

A linear scale or ruler, typically in inches or millimeters which has been lengthened by the percentage of linear shrinkage by which liquid metal contracts during solidification and cooling.

Sieve Analysis

See Screen Analysis

Silica

Silicon dioxide, the prime ingredient of sand and acid refractories.

Silica Brick

Refractory material of ganister, bonded with hydrated lime, and fired at high temperature.

Silica Gel

A colloidal form of silica used as a drying agent.

Silica Sand

Sand with a minimum silica content of 95% used for forming casting molds.

Silicon

An abundant element, chemically classed as a nonmetal, metallurgically a metal, used extensively in ferrous and nonferrous alloys; melting point 1423°C (2593.4°F)

Simultaneous Engineering

Refers to the process where user/designer and producer interact to reduce lead time and improve the efficiency of a part. This process is faster and more efficient than the traditional sequential process of design and manufacture.

Sintering

The bonding of adjacent surfaces of particles of a mass of powder or a compact by heating to a suitable temperature and cooling.

Sintering Point

That temperature at which the molding material begins to adhere to the casting, or in a test when the sand coheres to a platinum ribbon under controlled conditions. Also, the temperature at which sand grains begin to adhere to one another.

Shewed Tolerances

Tolerances which are non-symmetrically distributed about the design parameter.

Skim Core (Skimmer)

A flat core or tile placed in a mold to skim a flowing stream of metal. Commonly used in pouring basins, it hold back slag and dirt while clean metal passes underneath to the downsprue.
See Core Strainer

Skim Gate

A gating arrangement which changes the direction of flow of molten metal and prevents the passage of slag and other undesirable materials into the mold cavity.

Skimming

Removing or hold back dirt or slag from the surface of the molten metal before or during pouring.

Skin

A thin surface layer different chemically or structurally from the main mass of a metal object.

Skin-Drying

Drying the surface of the mold by direct application of heat.

SLA

See Stereolithography Apparatus

Slab Core

Flat, plain core.

Slag Inclusion

Nonmetallic solids entrapped in solid metal.

Slag Trap

An enlargement, dam, or extrusion in the gating or runners system in a mold for the purpose of preventing molten slag particles from entering the mold cavity.
See also Dirt Trap

Slicking (Sleeking)

Smoothing the surface of molds.

Slip Casting

In ceramics, a pouring slip, a water suspension of finely ground clay, into a plaster of paris mold. After it hardens it is dried and fired.

Slurry

A term loosely applied to any clay-like dispersion. It may be use to wash ladles or other refractory linings to impart a smooth surface; as a bonding addition to molding sand; as a thin loam over specially made molds or as a mixture to fine joints or cracks of a core, etc.

Smelting

A metallurgical thermal process in which a metal is separated in fused form from nonmetallic materials or other undesired metals with which it is associated.

Smoke

A type of emission resulting from incomplete combustion and consisting predominantly of small gas borne particles of combustible material present in sufficient quantity to be observable independently of the presence of other solids in the gas stream.

Soaking

Prolonged heating of a metal, furnace or ladle at a selected temperature.

Society of Automotive Engineers, Inc.

SAE

Sodium Silicate

See Water Glass

Softening

A process used to soften metals through annealing or tempering.

Soldering

1) Joining metals by fusion of alloys that have relatively low melting points - most commonly, lead-based or tin-based alloys, which are the soft solders. Hard solders are alloys that have sliver, copper, or nickel bases, and use of these alloys with melting points higher than 800°F (426.7°C) is generally termed brazing, 2) the sticking or adhering of molten metal to portions of a die.

Sold

That material which has a tendency to resist any attempt to change its size or shape.

Solidification

The physical process of change from a liquid to a solid state.

Solidification, Shrinkage

The decrease in size accompanying the freezing of a molten metal.

Sonic Testing

Using sound waves above audible frequency via a supersonic reflectoscope to measure time sound waves take returning from opposite sides of casting. Defects return the waves in more or less time.

Sorbite

Tempered martensite that has a micro-structure of distinctly granular appearance. Further tempering causes the appearance of clearly resolvable carbide particles (spheroidite).

SPAL Process

See Surface Protection Air Liquide

Spalling

Buckling or flaking off of the surface material.

Specific Gravity

A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water at 39°F (3.9°C), for which the specific gravity is taken as 1,000 kg/m3.
See also Density

Specific Heat

Equivalent to thermal capacity, or the quantity of heat required to produce a unit change in the temperature of a unit mass.

Specific Volume

Volume of one gram of a substance at a specific temperature, usually 68°F (20°C).

Spheroidite

A cementite aggregate of globular carbide and ferrite.

Spheroidized Cementite (Divorced Pearlite)

The globular condition of iron carbide after a spheroidizing treatment.

Spiegeleisen (Spiegel)

Alloy of iron and manganese used in basic and acid open hearth steelmaking practice. A high manganese pig iron, usually containing 15% or 20 Mn and 4.5-6.5% C.

Spiral Test

A method of interpreting the fluidity of an alloy by pouring molten metal into a mold with a long narrow channel. The length of such casting, under standardized conditions, is taken as the fluidity index of that alloy.

Splash Core

A core of tile placed in a mold to prevent erosion of the mold at places where metal impinges with more than normal force. Splash cores are commonly used at the bottom of large rammed pouring basins, at the bottom of long downsprues, or at the ingates of large molds.

Spongy Casting

A casting in which the metal is porous and dendritic.

Spout

A trough through which the metal flows from the furnace to the ladle.

Spary Quenching

After solution heat treating, a mode of quenching in which a spray of water is directed upon material just removed from the furnace.

Sprue Base

An enlargement or rounded section at the bottom of the downsprue, used to help streamline the flow of metal into the runner, lowering the velocity.

Sprue Bottom

A print attached to the top or squeeze board of a mold to make an impression in the cope indicating where the sprue should be cut.

Sprue Cutter

A metal tool used in cutting the pouring aperture, the sprue hole.

Sprue Hole

The opening through which the metal is poured into the cope to run into the casting cavity.

Squeeze Board

A board used on the cope half of the mold to permit squeezing of the mold.

Squeeze Head

In certain type of molding machines, a stationary or movable plate against which a filled mold is compressed, in order to complete the compacting of the sand.

Squeezer Machine

A power-operated, usually pneumatic, device used to pack sand into a flask.

Stack Molding

See Multiple Mold

Stainless Steel

A wide range of steels containing chromium or chromium and nickel, exhibiting high resistance to corrosion.

Standard Deviation

A statistical quantity used to describe the variation of a measurable attribute about some average value.

Standard Pattern

A pattern of high-grade material and workmanship in daily use or at frequent intervals. A pattern used as a master to make or check production patterns.

Standard Samples

A sample of know composition used to calibrate an instrument or method of analysis.

Standard Shapes

Refractory units stocked by manufacturers or made from stock molds.

Stave Construction

Attaching staves to polygonshaped heads in the building of cylindrical bodies; also, standard method used in making semicircular core boxes.

Steel

An alloy of iron and carbon that may contain other elements and in which the carbon content does not exceed about 1.7%; it must be malleable at some temperature while in the as-cast state.

Steels, SAE

Common designation for the standard grades of steel approved by the Society of Automotive Engineers.

Stellite

Proprietary name of a group of complex alloys retaining their hardness strength and resistance to oxidation at high temperatures; contains W, Co, Cr and C.

Steeped Construction

In patternmaking, the courses of material that when fastened together resemble steps.

Stereolithography Apparatus (SLA)

Equipment used for computerized building of three-dimensional models and patterns. Enables the data representation of a CAD solid model to be directly converted into a plastic model of a casting.

Sticker

A lump on the surface of a casting caused by a portion of the mold face sticking to the pattern. Also, a forming tool used in molding.

Stock Allowance

Material added to a part to allow for surface preparation or precise dimensioning by machining.

Stock Core

Core of standard diameter usually made on a core machine and kept on hand, sawed to required length.

Stool

Support for a green sand core on a molding machine.

Stool Plate

Plate on a mold machine on which stools are mounted.

Stooling

Supporting green sand cores in machine molding while pattern is being withdrawn.

Stopper Head

A refractory shape at the end of a stopper rod, usually clay and graphite, seated in a ladle's nozzle.

Stopper Rod

A device in a bottom-pour ladle for controlling the flow of metal through the nozzle into the casting. The stopper rod consists of a steel rod, protecting sleeves, and a graphite stopper head. It may also be a single piece manufactured from graphite.

Stopping-Off

Filling in a portion of a mold cavity which is not to be cast.

Strained Casting

A phrase used to describe the result when molten metal is poured into the mold at too fast a rate or under too great metallstatic pressure, causing the cope to rise slightly from the drag and resulting in an oversize casting.

Strainer Core

See Core Strainer

Streamline Flow

Steady flow of liquid without turbulence. Generally, not experienced in metalcasting.

Strength, Baked

Compressive, shear, tensile, or transverse strength of a molded sand mixture when baked at a temperature above 230°F (110°C) and then cooled to room temperature.

Strength, Compressive

See Compressive Strength

Strength, Impact

See Impact Strength

Strenght, Retained

Compressive, shear, tensile, or transverse strength attained by a sand mixture after being subjected to a cycle or cycles of heating and cooling which approximate foundry practice.

Strength, Shear

See Shear Strength

Strength, Tensile

See Tensile Strength

Strength, Yield

See Yield Strength

Stress-Corrosion Cracking

Spontaneous failure of metals by cracking under combined conditions of corrosion and stress, either residual or applied.

Stress, Relieving

A heat treatment to reduce residual stresses followed by sufficiently slow cooling to minimize development of new residual stresses.

Stress, Residual

Those stresses setup up in a metal as a result of nonuniform plastic deformation or the unequal cooling of a casting.

Strike-Off

Operation of removing excess sand from top or core box or flask.

Stripper Pins

On certain molding machines, a series of pins (usually four in number) which support the rammed flask-half at the parting surface so that the mounted pattern may be drawn by lowering.

Stripping

Removing the pattern from the mold or core box from core.

Stripping Time

In oil-oxygen and nobake mixture, the moment when the core box may be satisfactorily drawn from the core, or pattern from the sand.

Structure (Cast Structure)

The size and disposition of the constituents of a metal as cast.

Styroform Pattern

Expendable pattern of foamed plastic, especially polystyrene, use in manufacturing casting by the Full_Mold process.

Subcutaneous Blowhole

Blowholes at or near the surface of solidified metal, covered with a thin layer of metal. May also be called pinhole porosity.

Subzero Treatment

Refrigeration of steel to promote transformation of retained austenite.

Sulfur

A nonmetallic element, melting point 444°C (831.2°F) occurring as an undesirable tramp (trace) element in most ferrous alloys.

Sulfur Prints

A macrographic method of examining for the distribution of sulfide impurities, in which a sheet of wet acidified bromide paper is placed on the polished surface to be examined.

Superalloy

An alloy developed for very high temperature use where relatively high stresses are encountered and where oxidation resistance is needed.

Supercooling

Lowering the temperature of a molten metal below its liquidus during cooling.

Superduty Fireclay Brick

Having pce above 33 with less than 1.0 percent linear shrink in the 1599°C (2910°F) reheat test, and less than 4.0 percent loss in panel spalling test preheated at 1649°C (3000°F).

Superheat

Any increment of temperature above the melting point of a metal; sometimes construed to be any increment of temperature above normal casting temperatures introduced for the purpose of refining, alloying or improving fluidity.

Supersaturated

Metastable solution in which the dissolved material exceeds the amount the solvent can hold in normal equilibrium at the temperature and under the other conditions that prevail.

Supersonic Reflectoscope

An instrument for sending, receiving, and measuring sound waves over 20,000 cycles per second.

Supramor

An electromagnetic flaw detection ink for the rapid detection of subcutaneous and surface flaws in ferrous metals.

Surface Hardening

Conferring a superficial hardness to a steel while maintaining a relatively soft core.

Surface Protection Air Liquide (SPAL)

The use of liquid argon, liquid nitrogen, or carbon dioxide snow to minimize the reaction of air and molten metal that normally occurs in an induction furnace. The liquid or snow is fed onto the surface of the molten metal where it vaporizes, displacing the air thus reducing slag and oxygen levels.

Surface Texture

The roughness, waviness, lay or other characteristics of the surface of a part.

Surfacing

Depositing a filer metal on a metal surface by any method to obtain certain desired properties or dimensions.

Swell

A casting defect consisting of an increase in metal section due to the displacement of sand by metal pressure.

Swing Frame Grinder

A device for grinding large castings where the work remains stationary. This grinder, too large to be hand lifted, is usually suspended from a hoist.

Synthetic Molding Sand

Any sand compounded from selected individual materials which, when mixed together, produce a mixture of the proper physical and mechanical properties from which to make foundry molds.

System Sand

Foundry sand used in making molds and which eventually becomes the bulk of the sand used in the mechanical system or mechanized unit.
See also Sand

Temper

1) Reheating hardened, normalized or mechanically worked steel to a temperature below the critical range to soften it and improve impact strength.2) The moisture content of a sand at which any certain physical test value is obtained, i.e., temper with respect to green compressive strength, permeability, retained compressive strength, etc.3) To mix material with enough liquid to develop desired molding properties.

Temper Brittleness

Brittleness that results when certain steels are held within or cooled slowly through a certain range of temperature below the transformation range.The brittleness is revealed by notched-bar impact tests at room temperature or lower temperatures.

Temper Stressing

Quenching in water from the tempering temperature to improve fatigue strength.

Tempered Martensite

Martensite that has been heated to produce to BCC iron and a fine dispersion of iron carbide.

Temperature

Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales, as Centigrade, Fahrenheit, etc.

Temperature, Holding

1) Temperature above the critical phase transformation range at which castings are held as a part of the heat treatment cycle,2) The temperature maintained when metal is held in a furnace, usually prior to pouring.

Temperature, Pouring

The temperature of the metal as it is poured into the mold.

Tensile Strength

The maximum stress in uniaxial tension testing which a material will withstand prior to fracture.The ultimate tensile strength is calculated from the maximum load applied during the test divided by the original cross-sectional area.

Ternary Alloy

An alloy that contains three principal elements.

Test Lug

An ear like projection cast as part of the casting and later removed for testing purposes.

Thermal Conductivity

The property of matter by which heat energy is transmitted through particles in contact.For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree Fahrenheit, and for a thickness of one inch, Btu/hr·ft·F/in.

Thermal Contraction

The decrease in a linear dimension and volume of a material accompanying a change of temperature.

Thermal Expansion

The increase in a linear dimension and volume of a material accompanying a change of temperature.

Thermal Fatigue

Failure resulting from rapid cycles of alternate heating and cooling.

Thermal Shock

Stress developed by rapid and uneven heating of a material.

Thermal Spalling

Breaking up of refractory from stresses which arise during repeated heating and cooling.

Thermal Stability

Resistance of a material to drastic changes in temperature.

Thermocouple

A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential which varies with the temperature of the junction.Thermocouples are used to operate temperature indicators or heat controls.

Thermography

1) The technique of obtaining a photographic record of heat distribution in a solid or fluid.

Tie Bar, Rod

Bar or rod-shaped part of the casting added to prevent distortion caused by uneven contraction between separated members.

Tight Flask

A type of flask which remains on mold during pouring.Lugs are normally provided for clamping cope and drag together for pouring.

Titanium

A white metallic element, melting point 1660°C (3020°F), having a high strength-to-weight ratio; useful in aircraft parts.

Tolerance

The permissible deviation of a dimension from the nominal or desired value.Minimum clearance between mating parts.

Tool Steel

Any high-carbon or alloy steel used to make a cutting tool for machining metals and for metal-casting dies.

Tooling Points

The fixed positions on the casting surfaces used for references during layout and machining.

Toughness

The ability of the metal to absorb energy and to deform plastically during fracture.Toughness values obtained in testing depend upon the test temperature, the rate of loading, the size of the test specimen, as well as the presence of a notch and its acuity.

Tower Oven

Vertical, continuous core oven with suspended shelves attached to sprocket-driven chains.

Tramp Element (Trace)

Contaminant in the components of a furnace charge, or in the molten metal or casting, whose presence is felt to be eitherunimportant or undesirable to the quality of the casting.

Transfer Ladle

A ladle that may be supported on a monorail or carried in a shank and used to transfer metal from the melting furnace to the holding furnace or from furnace to pouring ladles.

Transformation (Temperature) Range

The critical temperature at which a change in phase occurs. To distinguish between the critical points in heating and cooling those in heating are referred to as the Ac points (c for Chauffage or heating) and those in cooling, Ar. (r for Refroidissement)

Tungsten

Steel-gray, metallic element, mp 3380°C (6116°F) used for electric lamp filament, x-ray tube target, and as alloy element in high-speed steels.

Turntable

The base on which a centrifugal casting mold rests.

Ultrasonic Cleaning

Immersion cleaning aided by ultrasonic waves which cause microagitation.

Ultrasonic Testing

A nondestructive method of testing metal for flaws based on the fact that ultrasonic waves are reflected and refracted at the boundaries of a solid medium.

Undercooling

See Supercooling

Unkilled Steel

A wild steel insufficiently deoxidized so that it evolves gas and blowholes during solidification.

Upgrading

In castings, the removal and repair of discontinuities to raise the quality level of the casting beyond that which can be economically achieved by good foundry practice.

Upper Yield Point (also Yield Point)

Denoted in yield point phenomenon as a distinct break from the elastic region accompanied by a drop in load, yet prior to plastic deformation in the stress-strain curve in a low-carbon steel.

Urea Formaldehyde Resin

A thermosetting product of condensation from urea or thio-urea and formaldehyde, soluble in water and used as a sand binder in core and mold compounds.

Vacuum Casting

A casting in which metal is melted and poured under very low atmospheric pressure; a form of permanent mold casting where the mold is inserted into liquid metal, vacuum is applied, and metal drawn up into the cavity.

Vacuum Degassing

The use of a vacuum technique to remove dissolved gases from molten alloys.

Vacuum Refining

Melting in a vacuum, usually by electrical induction, to remove gaseous contaminants from the metal.

Value Analysis

In manufacturing, an analysis to determine the most economical method of manufacturing, taking into account the cost and the process capability of alternate manufacturing systems under consideration, their degree of variation, the benefits of the resultant product, and desired quality and production quantity and rate.

Vanadium

A white, hard, metallic element, mp 1800°C (3272°F), used as an alloy in iron and steel; a powerful carbide stabilizer and deoxidizer.

Vegetable Oils

Oils extracted from plants, used as drying oils in oil core manufacture. Linseed oil is an example.

Veins

A discontinuity on the surface of a casting appearing as a raised, narrow, linear ridge that forms upon cracking of the sand mold or core due to expansion of the sand during filling of the mold with molten metal.

Venting

Perforation with a vent wire of the sand over and around a mold cavity to assist in the escape of the gases.

Vertical Axis Casting Machine

A centrifugal casting machine in which the axis of rotation of the mold is vertical.

Virbrator

A device, operated by compressed air of electricity, for loosening and withdrawing patterns from a mold, or for vibrating a hopper or chute to promote the flow of material from the hopper or chute.

Vicers Diamond Pyramid Hardness Tester

Patented indentation hardness machine. See Hardness

Virgin Metal (Primary Metal)

Metal extracted directly from the ore; not previously used.

Viscosity

The resistance of fluid substance to flowing, quantitatively characteristic for an individual substance at a given temperature and under other definite external conditions.

Void

A shrinkage cavity produced in casting during solidification.

Warpage

Deformation other than contraction that develops in a casting between solidification and room temperature; also, distortion occurring during annealing, stress relieving, and high-temperature service.

Wash

A casting defect resulting from erosion of sand by metal flowing over the mold or corded surfaces. They appear as rough spots and excess metal on the casting surface. Also call cuts.

Washburn Core

A thin core which constricts the riser at the point of attachment to the casting. The thin core heats quickly and promotes feeding of the casting. Riser removal cost is minimized.

Water Test

To subject a casting to water pressure in such a manner that any porous areas will show leakage.

Water Glass

Sodium silicate (an inorganic binder system), a viscous liquid which when mixed with powered fireclay forms a refractory cement.

Wax Pattern

1) A precise duplicate, allowing for shrinkage, of the casting and required gates, usually formed by pouring or injecting molten wax into a die or mold, 2) wax molded around the parts to be welded by a termite welding process.

Wear

The undesired deterioration of a component by the removal of material from its surface.

Weld Bead

The built-up portion of a fusion weld, formed either from the filler metal or the melting of the parent metal.

Welding

A process used to join metals by the application of heat. Fusion welding, which includes gas, arc, and resistance welding, requires that the parent metals be melted.

Welding, Arc

Welding accomplished by using an electric arc that can be formed between a metal or carbon electrode and the metal being welded; between two separate electrodes, as in atomic hydrogen welding or between the two separate pieces being welded, as in flash welding.

Welding, Autogenous

Method of uniting two pieces of metal by melting their edges together without solder or any added welding metal, as by the thermite process that employs a medium of finely divided aluminum powder and oxide or iron by which a temperature of some 2982.2°C (5400°F) is obtained.

Welding Electrode

A metal or alloy in rod or wire forms used in electric arc welding to maintain the arc and at the same time supply molten metal or alloy at the point where the weld is to be accomplished.

Welding Flash

Skin exposed too long to the ultraviolet rays of welding or melting arcs will burn as in a sunburn. Though temporary blindness can result, it is not permanent, as is popularly believed.

Welding Shielded-Arc

Electric-arc welding in which the molten weld metal is protected from the atmosphere. An inert gaseous atmosphere or fluxcoated electrode may be employed.

Welding Stress

That stress resulting from localized heating and cooling of metal during welding.

Wet Scrubber (Gas Washer)

In air pollution control, a liquid (usually water) spray device for collecting pollutants in escaping foundry gases.

Widmanstatten Structure

Plate-like structure seen in grains of steel in the course of transformation of a solid solution.

Wild Steel

Steel which has not been completely deoxidized and reacts violently after casting due to liberation of gases of cooling.

X-Ray

Form of radiant energy with wavelength shorter than that of visible light and with the ability to penetrate materials that absorb or reflect ordinary light. X-rays are usually produced by bombarding a metallic target with electrons in a high vacuum. In nuclear reactions it is customary to refer to photons originating in the nucleus as gamma rays and to those originating in the extranuclear part of the atom as x-rays.

Yield

Comparison of casting weight to total weight of metal poured into mold.

Yield Ratio

The ratio of yield strength to ultimate tensile strength.

Yield Strength

The stress at which a material exhibits a specified limiting permanent strain.

Young's Modulus (E)

See Modulus of Elasticity

Zircon

The mineral zircon silicate, ZrSiO4, a very high melting point acid refractory material used as a molding material in steel foundries.

Zirconia

ZrO2 an acid refractory up to 2500°C (4532°F) having good thermal shock resistance and low electrical resistively.

Zirconium

Silvery-white, metallic element, melting point 1860°C (3380°F), a powerful deoxidizer when added to molten steel.

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