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