The process of black oxide is a chemical reaction between the iron of the ferrous alloy and the hot oxide salt bath producing a magnetite on the surface. Formation of black iron oxide occurs through the process allowing for increased corrosion protection. The typical thickness is about 0.00003 inches.
This coating does not change the dimensional, physical or mechanical properties of the finished product. In addition, the finish is inexpensive. It can be used on a wide range of products from hand tools and firearms parts to fasteners and engine parts.
Some benefits of this coating are:
- Corrosion resistance when oiled
- Attractive finish
- No dimensional change