Black Oxide Coating
Black oxide (blackening, oxidizing, black passivating, gun bluing), is a type of conversion coating process. Metals with a black oxide coating are dimensionally stable and have a matte black appearance. Unlike nickel or zinc electroplating, the black oxide is not deposited on the surface of the substrate. Instead, we create the black oxide coating via a chemical reaction between the iron of the ferrous alloy and the oxidizing salts present in the hot black oxide solution.