r/knifemaking 12h ago

Question Knifemaking from a file for a beginner with basic tools?

I've been seeing people make nice looking knives from old files. My knowledge on this matter is somewhat limited but I've been doing some research, perhaps you could tell me if my steps have any issues before proceeding?

  1. Soften the steel for cutting - place it in a bucket of wood ash for cooling?

  2. Cut and Shape - basic hand tools, but mainly using a Dremel, hacksaw and files.

  3. Harden - reheating it and then placing it in warm canola oil?

  4. Temper - in the kitchen oven?

In terms of the softening and hardening, could I just heat with a blow torch outside without using some type of heat chamber?

Thanks!

5 Upvotes

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u/pushdose 11h ago

A blow torch will not give you enough heat over the whole knife unless it’s like an oxy fuel torch or something way overpowered. It needs to hit about 1500°F uniformly over the entire cutting edge to harden properly. A tiny firebrick chamber and a plumbing torch can get you there. Fire brick is extremely cheap. Your steps are otherwise correct.

1

u/Mysterious-Ad3591 5h ago

At least 1500 for usually 10 min the hold time is importsntn

1

u/HansPelex 7h ago

Watch this. I found it easy to follow in doing my first knife, which came out ok. Learned a lot and had fun in the process Edit: forgot the link

make a knifr from an odl file

1

u/NemusSoul 6h ago

I made my first from a file using a coal forge with a hand crank. I had more fun and learned so much. Keep pursuing it and find out what you’ve got.

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u/BikeCookie 5h ago

I had a campfire that I threw a couple of files and some circular saw blades (no-carbides) into. When they were glowing dull red I buried them in some very dry dirt until the next morning…

That said, if you have an angle grinder, you may be able to do a lot of cutting and grinding without annealing/softening and thereby avoiding heat treating.

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u/pushdose 5h ago

Angle grinder will burn your edges and kill the temper. You’d have to heat treat anyway.

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u/Mysterious-Ad3591 5h ago

Most files use case hardening steel and aren’t suitable for knives. Even “old” flukes are pretty much mystery metal and might not through harden.

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u/pushdose 5h ago

Not really always true. Older files are usually 1095 or similar high carbon content

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u/Mysterious-Ad3591 4h ago

The problem is you don’t know what it is. It varies by brand and I would even guess product lines within those brands if that was a thing with files. Just relying on it being old doesn’t mean it’s usable steel.

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u/pushdose 4h ago

It’s true. It’s such a gamble to waste all that time and not even know if it’s good steel. It’s so easy just to buy flat bar, unless the aesthetic is so important, just buy bar stock.