Question for the knife makers

[DC]

I want to make a new blade for my scraper. I'm thinking of using an old file. I'm concerned with rolling a hook in the edge. If it's too hard it would just crack and it it's too soft it wouldn't last. I can harden the metal no problem but what temperature would I temper it to?

[bubby]

You can use an angle grinder to get clost to your shape ans not worry about it getting hot, then heat to non magnetic and let completely cool , do that 3 times then heat to nonmagnetic and let it soak at that for a few mins and quench in oil, then clean the scale from it and put in the oven at 450 about an hour, it should have a nice straw color and the you can roll the bur on it

[Tracker0721]

that stuff^

But I thought knives were tempered around 400 for file material and temp increased based on hardness? I could be 1000% off as I've yet to temper a file knife though. Asking to learn more.

[willie]

I think you are right tracker.

if the file is still at its original temper, there would be no reason to anneal and reharden.

just retemper. if the 450 for an hour doesn't draw enough hardness back out, then try again at 500....etc

unfortunately, if you draw too much out and don't like the edge holding, then you have to start all over by rehardening

older 1095 should respond to a tempering draw down, I don't know about the chineeese cheapies,  think they use some sort of case hardening, but why not put one in the oven (if you got one) and let us know.

[DC]

450 for an hour that's what I was after. I'll probably try without annealing. I'll just keep it wet while I'm grinding.

[bubby]

Yikes after ht i meant 400, 450 to anneal like tracker said, lolmust of saw a squirrel 😉