Chromating is a conversion coating process in which an oxide layer is deposited over a metal surface to allow the metal to react with the oxide layer. This forms a passive metal chromate layer on the surface.

Chromating typically acts like a coat pf paint on zinc, protecting the zinc surface from whiteout corrosion and increasing the durability of the zinc component severalfold, depending on the thickness of the coating. The darker chromate coating provides higher corrosion resistance, thereby increasing its service life.