Blackening Steel


I seem to remember reading long ago a technique for blackening mild steel by heating it to a certain temperature, then quenching in used motor oil or some similar material. Can anyone refresh my memory?

Thanks, Jason

Reply to
Loading thread data ...


I think 350 F should work, no need to heat to a read heat. I think people recommend "used" motor oil because it's cheap, not because the combustion waste products in the oil add anything to the process, possibly other than cancer :) Most any oil new or used should work fine. It may take several dips to get the color you want.


Reply to

Basically you want enough heat to cause the oil to smoke, but not ignite when oil is wiped onto the part.

For blacksmithed stuff, I have used canola oil and it works well.

Another useful thing I have found is to use cold blue from the gun store, and apply it to the piece while the piece is hot. The result, once oiled, looks somewhat like color case hardening.

Cheers Trevor Jones

Reply to
Trevor Jones

Thanks everybody for the input. I didnt realize this has come up so often, I've been here for a few months now, and never noticed the topic. The reason I ask, I'm going to try it soon, as a buddy at work wants to darken some pieces, and he wants me to chuck them on the lathe for some decorative handles or something.

Thanks aga>

Reply to

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.