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What is blackened steel?  

August 6, 2007

What is blackened steel; a finish? What is best way to specify this?
If a finish, is it typically done to a specific type of steel for this effect?
Eg. blackened steel treads and risers for a stair.
Thanks

Ann Marciano
Specifier - Morganville, NJ

I don't think that "blackened steel" is a codename or special industry lingo for anything, Ann; I think it really just means steel that has been blackened in some way. So "black oxided" may be as good a definition as any. In this process the steel is cleaned, acid activated, then dipped into a vat of hot strong caustic plus some nitrates or other oxidizers, which forms a black oxide product on the surface. While it's applicable to most any kind of steel, I don't think it's terribly durable or very rust resistant. So if you want a more durable coating you may need to specify a black nickel plating, black chrome plating, or zinc plating with black chromate conversion coating.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Thank you Ted.

Ann Marciano
- Morganville, NJ