Heat Treating Punches

[Archie Zietman]

Hey,
I just forged myself two punches out of some old railroad tie (similar to 3/4 inch round 5160). How shall I go a bout heat treating them? Do I want them hard or soft? Hard in one place soft in another?

Thanks,
Archie

[Steve Sells]

hard at punch end, soft where the hammer hits it, is a good start.

[brianbrazealblacksmith]

For heat treating small hand punches and chisels used to forge with made from 5160, I bring only about 3/4" from the working end of the tool up to temp then quench about 3/8" in water, moving the tool back and forth and slightly up and down. [Do not over heat. Do not cool off too much. You'll hear a little ping if you cool too much, which means it just broke across its profile.]Now with the heat remaining in the tool I draw the temper from straw to blue depending on the tool, cool the same 3/8", scratch or brush, and draw the temper again, repete if I still have heat. Once I can no longer draw a temper, I cool the whole tool in water so I can use it. I always tap the finished tool over the horn of the anvil a few times. If I did something wrong it will break across its profile. That's how I've been doing it, and Alfred Habermann was doing pretty much the same thing, but I've also heard that you're never supposd to quench spring in water. I also treat small punches and chisels made from 4140 and 1050 in the same manner. Larger bodied tools, I treat differently.