AMS 2400

Cadmium plating is a process which electro-chemically deposits a thin coating of cadmium on a base metal. It's primary purpose is corrosion resistance, lubricity, conductivity and solderablility. Most aircraft fasteners are cadmium plated for the corrosion resistance and lubricity. Electrical conducting parts are sometimes plated to keep the base metal from corroding and reducing conductivity. Cadmium plating is also used as a sacrificial coating between stainless steel and aluminum to keep a galvanic reaction from occuring.

Cadmium metal is considered a toxic metal by the US EPA and many countries overseas. Therefore many items which were once cadmium plated are now protected by other metals. Because of the properies of cadmium no single cost effective alternative has been found for every application, especially in the U.S. military. Using cadmium in many applications can be justified by comparing the effects on the environment with cadmium substitutes.

Typical thicknesses for cadmium plating are 0.0002" to 0.0005". Clear, yellow and olive drab chromates are available post treatments and the corrosion resistance increases with the darkness of the chromate without the part getting powdery.