When sheet metal components are joined and they are to be touching, it is necessary to dimple the material to flush mount the attaching screws. Being that the flanges of the Latch and Receiver cases are also dimpled, a buildup of the simple “stack” occurs as shown below.

Obviously this adds to the gap between the case flange faces and must be factored into the “setbacks” chosen to maintain approximately the proper “reach” of the Latch hook. The S1500-3-750 latch chosen in this assembly has a ‘reach’ of 1.500”, which satisfactorily matches the 1.477”/37.5mm span between the Latch hex and the Receiver pin.