Electro-Polish Co

Black Oxide

For over 65 years Electro Polish has provided fully certified black oxide finishing. Our two tank Dulite solution provides for deeper penetration giving you a more resilient, richer black finish that is ready for extended service…all of this with no effect on the dimensions of your parts.Whether it’s hardened tool steels, stainless steels, or cast iron you will not see the red and brown finishes inherent to the other black oxide methods. At Electro Polish Co. we will get your parts blacker than you ever imagined. You’ll see the difference!

Black oxide is a process that chemically alters the outer layer of certain metals to create a protective coating. This coating is integral to the surface of the part and therefore will not chip, peel, flake, or rub off. Additionally, no dimensional change of the part occurs during the process. This is to be contrasted with applied coatings, such as paint, that do change the dimensions of a part and will chip or peel. A black oxide coating provides an excellent pretreatment for paint, increasing the adhesion qualities of the metal. Black oxide is typically applied to ferrous alloys like steel, where the iron in the material reacts with oxidizing salts to form magnetite (Fe304). Electrical conductivity is not affected by this chemical compound.