Feature A, the circular knuckles (4”diameter) on the small tabs are 1.6” thick to provide strength and stiffness. The walls connecting the tabs to the main ring are 0.86” thick.

-- The difference in thickness between the tabs and the connecting wall will produce a hot spot.

The drawing shows the feed pads (in red) added to the walls to prevent thermal isolation and promote metal feed into the knuckle section.

-- The pads also serve to stiffen and strengthen the small tabs.