The .405-.812 MS27183 Military Flat Washer Cadmium is a thin, flat washer with a large outer diameter and a small inner diameter. It is made of cadmium-plated steel and has a thickness of .032 inches. The washer is used to distribute the load of a bolt or screw over a larger area, preventing the bolt or screw from pulling through the material it is securing. It is commonly used in military and aerospace applications, as well as in other industries where high strength and durability are required.