What is PVD Black?
PVD stands for Physical Vapor Deposition and is a highly accurate plating process carried out in high vacuum environments at temperatures between 150 and 500 *C. It produces a highly durable finish to prevent scratching. PVD plating is used to plate high-end watch hardware, golf clubs, etc., and the only successful way to make a black that will not wear off.
Black Oxide
Black oxide process applies to ferrous, non-ferrous, brass, and copper alloy. Black Oxide is a true conversion coating converting iron to the naturally occurring black iron oxide compound called magnetite. The magnetite is produced through a chemical reaction as the alloy is immersed in the hot blackening solution.