Black oxide FAQs


Does the coating chip or flake off?

NO - there is no hydrogen embrittlement with black oxide...unlike plated and painted parts that are acid etched.

How long will black oxide finish resist corrosion?

Up to 144 hours - depending on the oil that is used and process parameters.

What is the thickness of the black oxide coating?

Virtually Zero - because the surface is converted (not coated).  No more than 5 to 10 millionths of an inch are added to the dimension of a part, which is comparable to the depth of penetration.  Unlike painted of plated surfaces, this process provides corrosion resistance for critical sized parts.  Is that cool or what?

Is it weldable?

YES - and it does not produce caustic fumes.  Unlike paint and plating, black oxide does not produce harmful fumes when welding.

What is black oxide?

MAGNETITE (Magnet) - The Black Oxide finish is a result of the surface being converted (does not add to it)  into Magnetite (Fe3O4).  It is formed by a chemical reaction produced when the part's iron ferrous alloy surface is immersed in an alkaline aqueous salt solution bath.  

Is it conductive?

YES - Black oxide coating is suitable for electrical parts as they do not reduce conductivity more than 1%.