This is an aluminum ground contact for a dummy load - a shallow cup with a bowl-shaped recess turned into the face and a countersunk hole through the centre. We turned it inside and out on the lathe - the outside profile and the O-ring groove, then the dished interior and the centre hole. The bowl and the OD are all curves and blends, so it's a part that lives or dies on the finish passes. It's a clean lathe job in aluminum, start to finish.

Material: Aluminum | Operations: Turning, Drilling | Size: around 113 mm dia, ~28 mm tall | Feature: dished recess, countersunk centre hole, O-ring groove