Thread: Kasenit or similar

Did case hardening back in trade school years ago and a couple of time at work. Don't remember if it was kasenit bit it was a carbon rich compound that you treated the outside with. Let you use a softer more easily worked material but then hardened the crap out of it once quenched.
Wasn't difficult on the parts we did (pins punches etc) but nothing like a frame or receiver. haven't done it for years