Black Oxide

Our Black Oxide coating process is a chemical conversion coating process that offers protection for the surface of the parts, without adding any coating thickness to the parts. This is great for tight tolerance parts.

What is Black Oxide?

The black oxide process is a chemical conversion coating. This means that the black oxide is not deposited on the surface of the substrate like nickel or zinc electroplating. Instead, the black oxide coating is produced by a chemical reaction between the iron on the surface of the ferrous metal and the oxidizing salts present in the black oxide solution. These oxidizing salts include penetrates, catalysts, activators and proprietary additives which all take part in the chemical reaction. The result of this chemical reaction is the formation of black iron oxide, magnetite (Fe3O4), on the surface of the metal being coated.

Oil post treatments are frequently used after black oxide coating. The oil can be either water-soluble or water displacing and can be controlled so that a fairly heavy oil film is left on the part or so that the part is virtually dry to the touch. Of course, less oil means less corrosion protection.

Our Process Includes:

Alkaline Cleaning to remove all oil and debris from parts or components.

Acid / Pickle Bath to etch parts allowing the black oxide chemicals to penetrate surface of the parts.

Blacking – Chemical bath for formation of black iron oxide on the surface of the parts.

Dry Touch Oil bath to enhance corrosion protection.

Typical Examples of Black Oxide Finish

black oxide example
black oxide example
black oxide example
black oxide example