Hardened my own tool steel with a toaster oven and it worked fine

Everyone says you need a proper forge or kiln to heat treat tool steel. I needed a small chisel for a specific job last month, and my propane forge was down. I stuck the blank in a toaster oven at 450 for an hour, then quenched it in vegetable oil. Did it chip on the first test? No, it held an edge through 20 strikes on mild steel. Is it perfect? Probably not, but it worked for what I needed. Anyone else use a janky setup like this and get decent results?

3 comments

3 Comments

stella_scott964d ago

oh man that reminds me of my buddy Dave... he once needed a tiny knife blank heat treated for a fishing trip like two days before we left. His regular setup was down and he was freaking out so he just stuck the thing in his girlfriend's toaster oven while she was at work. 400 degrees for like 45 minutes then dunked it in canola oil because that's all he had. He was so scared it would crack but we used that knife to cut rope and gut fish all weekend and it was fine. not like a pro knife but it got the job done. he still has it actually but his girlfriend was real mad about the toaster oven smelling weird for a week...

fionafoster4d ago

Maybe it's just me but I once tried to harden a cheap fish scraper in my apartment oven and forgot about it until the smoke alarm went off and my neighbor thought I was cooking meth.

adam_baker4d ago

400 degrees is way too low for real heat treating on most steels, man. You need closer to 1500 for the actual hardening phase. But if it was a small blank and already mostly hard from the factory, that toaster oven trick might have just tempered it a bit. I've done something similar with a cheap kitchen knife I messed up the edge on. Stuck it in a gas oven at 350 for an hour because I didn't care if it wrecked the blade. Came out okayish. The oil dunk thing is risky too unless you know the steel type. Canola has a low smoke point so it catches fire easy. But hey @stella_scott96 your buddy got lucky. That knife probably would have shattered if he tried to bend it much.