Summary for blackened steel Discussion
Blackened steel is generally just steel that has been blackened in some way, according to Ted Mooney, rather than a special industry term. He suggests that “black oxided” is a fair description: the steel is cleaned, acid activated, then treated in a hot caustic bath with nitrates or other oxidizers to form a black oxide surface. Ted notes that this can be applied to most kinds of steel, but warns it is not especially durable or rust resistant. For applications like blackened steel treads and risers on a stair, he says a more durable finish may need to be specified instead, such as black nickel plating, black chrome plating, or zinc plating with black chromate conversion coating. The thread is essentially about how to specify the finish and what alternatives may perform better.
Q. 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, New Jersey
2007
A. 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.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
2007
Thank you Ted.
Ann Marciano [returning]
– Morganville, New Jersey
2007