How do you heat it up (torch with rosebud, a friends gas forge, an electric jewelers oven)?
It is hard to evenly heat a knife with a torch. Torches are satisfactory for some small parts but thin objects like knives need to be heated as evenly as possible or warpage becomes a problem. The forge (coal, gas or oil) or oven would work, I’ve never used electric but I expect it is easier to control (if it gets hot enough). Preheat your oven so that the part doesn’t have to spend a long time heating. Long heat times near more oxidation. The most common error is overheating prior to quenching. I’ve never done it but if you have inert gases in your shop (helium, argon, CO2), you could pipe a little in to that jewelers furnace and cut down on oxidation. Another good method is to use stainless steel foil. The part is sealed in a stainless foil bag, heated, then the bag is ripped open and the part quenched. Its expensive by the roll ($100 US) but you may be able to talk a local machine shop or heat treater into selling you a few feet. You can also purge the package with inert gas to redu
