plating, anodizing, & finishing Q&As since 1989
Best stainless alloy for scratch resistance
May 16, 2012
Q. I'm researching for the proper stainless Alloy to use on A Therapeutic Patent- approved Tool that is resistant to scratches. I have tried 304 & 316 plate to polish, It continues to have surface scratches. Do I need to take the next step & have the Tool Heat treated or a separate stainless alloy application? 1/4" plate Is Needed....
Thanks For Your Interest
Patent approval on therapeutic massage tool - Davenport, Iowa
A. Hi Eric!
When I think scratch resistance, I think of the cutlery grade stainless steels like 420 and 440C. Knives are made from them, so get a stainless knife and see if it is sufficiently scratch resistant for your purposes. It will need to be heat treated for hardening, after you've machined or formed it into your part.
The stainlesss steels you mentioned, 304 etc, can't be hardened by heat treatment. Except by nitriding, and then you lose your corrosion resistance. Or maybe by Bodycote's Kolsterising process, which sounds like it might work for you.
metallurgist - E. Aurora, New York
I don't really get into alloy selection too much, my customers generally already know what they are using before they come to me, but I do know that the 400 grades are used far more than the 300 grades for things that require material hardness, for instance a surgical blade that must retain its cutting edge for as long as possible. I suggest you do an internet search on "stainless steel hardness".
Stellar Solutions, Inc.