Tom , as most know I do things differently LOL . When I make a punch for punch HOT steel , I dont see a need in hardening it and tempering it, cause if your punchs through something thick and forget to cool off then you just drawn your temper out of it. By the way I make my punchs out of 5/8" 5160. Thats the way I do it , may not be the politictily correct way but it works for ME , and thats what I think is important that it works . Just my .02 cents worth.
Chris