Black Oxide / Bluing is a passivation process in which steel is partially protected against rust, and is named after the blue-black appearance of the resulting protective finish.

Black oxide is a conversion coating formed by a chemical reaction when immersed in alkaline salt solution at approximately 285 degrees F. the surface of the part may be shiny or matte depending on the beginning surface of the part. For example, a polished surface will retain its luster after black oxidizing. Black oxide provides minimal protection against corrosion, unless also treated with a water-displacing oil or wax to protect finish.

Black oxide does not require acid activation nor is it an electro-process; therefore, hydrogen embrittlement is not a factor. We Black Oxide to MIL-SPEC C-13924C Class 1.

Black Oxide / Bluing Benefits

- No dimensional changes
- Reduces glare
- Finish will not chip, peel, flake, or rub off