Best etch for hardened steel?

Acid etchants for steel are usually nitric acid, or a mix of nitric and hydrochloric.

For your applications, especially if you have a fair number to do, I recommend electrochemical etching instead.

Jim

I had a knife maker friend that used ferric chloride (Archer Etchant from Radio Shack). Don't know if it works on SS. check the knife making sites. Karl

Ferric chloride is too slow on steel to make a crisp etch. It will eventually produce a shallow etch, but undercuts horribly.

Jim

Consider using shelf liner for the " resist " and then using a sand blaster to lightly etch it. The shelf liner will not last for a heavy blasting, but will work.

Dan

You might consider this: Back in the early 60's when I was a grad student, we wanted an interesting and different birthday present for my mother in law but had the usual grad student bugetary constraints. We bought a pair of quality sewing scissors. I dismanteled them and coated one blade with Kodak photo resist. I then carefully placed the word MOR (Danish for mother) on the dried KPR with black Letraset, exposed this to UV for several minutes and developed the image with KPR Developer. I then placed a little puddle of Ferric Chloride solution (printed circuit board etch - Radio Shack have it) on the area and let it work for a few minutes. I then rinsed it thouroughly with water and Gold plated it through the resist. I built up my own brush plating setup but today you can buy the stuff from

She had those scissors 'til she died and my wife inherited them - none of the family would DARE walk off with them!