"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



If I was making the plug gage, and I didn't have a controlled atmosphere
furnace ( which I don't), I'd bead blast the entire gage after heat treat,
just before grinding. I'd heat treat the entire gage, not just the plug
end. Bead blasting removes all the scale and leaves a very pleasing
finish. All depends on the size of the media you use, of course. Very
fine sand (aluminum oxide, really) does a bang up job, too.

Harold