[TheForge] S1 Heat Treating

[Ed F]

A while ago George Dixon posted a procedure for quenching H13 and/or S7 in salt water.  It shocked me but I did try it on an S1 punch that I was using for cold work in my flypress and it held up much better than air quenching it had.  I had good luck with several punches afterward and gained confidence, but of course when quenching some punches I put a lot of work into it bit me.  When cleaning them up I realized that most of them cracked.  I think I can get the one time hot impression I need from them (although I wanted to use them after this project, of course)  but I'm wondering what I might do next time.

I think the problems may be related to the "care" I was taking to heat them slowly in the gas forge and let them soak a bit.  Typically, I just use a torch to heat the little 5/8 diameter x 2" long punches.  Some punches I heat treated afterward weren't in the forge nearly as long (10 minutes vs. 20 or 30 mins) and didn't crack.

Ed