BFG performs a variety of processes to meet the specific requirements of a part. They include: Zinc, Plating, Resin, Impregnation, Zinc Phosphate Coating, Manganese, Phosphate Coating, Black Oxide Coating, Leachant Sealer, Copper Coloring, Color Marking (for part differentiation)

http://www.bfgelectroplating.com/

A metal finishing company that applies black oxide finishing for steel, stainless steel, and copper applications.

http://www.clevelandblackoxide.com

Black Oxide Passivation and Phosphating Specializing in Barrel Plating.

http://www.swdinc.com