Heat treating S7

[rhrocker]

I bought some S7 from McCarr a while back for the purpose of making some hand tools, like chisels, fullers, punches, slitters, drifts, etc. I believe it comes annealed, but I don't
know how one would heat treat tools like this. Does anyone have any ideas? These rods are 5/8's in diameter, and each tool will be about 7" long. About 2/3's the length will be for gripping by hand, and for striking with a hammer. The other end of course is to be the working end. The ends will be shaped both by stock removal, and forging.
Appreciate any suggestions!
Robert

[Doug Lester]

The info that I have on S7 is a little limited but I see, due it's chromium and Molybdenum content, that it's air quenching. That means that you will have to anneal after forging as it cannot be normalized. You may have to close it up in a hot forge and let them cool off together if you don't have a heat treating oven. Hrisoulas states to preheat the steel at 1200-1300 degrees for 5 minutes prior to heating to forging temperatures and to forge between 1700 and 2050 degrees which, if I remember correctly is orange to yellow. Anneal immediately after forging. Due to the Molybdenum content the steel is going to be red hard and slow to move under the hammer. It looks like you could temper at around 400-450 degrees and get an HRC in the mid 50's.

Doug Lester

[rhrocker]

Appreciate it Doug. Looks like the annealing may be one of those complicated (for me)
negative ramped ones. I have a Evenheat, not sure if it goes backerds or not

[Doug Lester]

Good luck with your projects. You may be right about the annealing, so many degrees per hour. Unfortunantly I don't have that kind of information on S7.

Doug Lester