Parkerizing is a type of firearms finish in which the parts are dipped into manganese phosphoric acid, or sometimes zinc, creating corrosion and wear resistant finish. This finish has been used by military forces around the world to protect their firearms in the harshest conditions. Manganese phosphating creates a medium – dark grey almost black, non-reflective, matte type finish on the parts to which it is applied. Parkerizing cannot be applied to non-ferrous metals such as aluminum, brass, or copper. Furthermore, it cannot be applied to steels with a high nickel content or on stainless steels.
Parkerizing prices start at $200.