A good way to remove scale after hardening is with sand blasting. You might
be able to do it chemically but that sounds dangerous (for both you and your
tools).

Out of curiosity, how are you grinding and lapping the gauge? Do you have a
cylindrical grinder? A lathe with a tool post grinder? Always looking for
new ways to do things...

Regards,

Robin


"Jeffrey Lindemuth" wrote in message
...
I want to make a plug gauge using O1 tool steel. I am going to harden,
grind and lap the gauge and knurl the handle. So if I harden the entire
piece, how do I get the scale out of the knurls? Or do I heat the entire
piece, only quench the plug end, let the handle cool slowly keeping the
handle annealed, remove the scale and knurl? Or do I not have a clue what
I
am talking about?

Jeff Lindemuth