Making Knife Blades From An Old File

Howdy Folks! This is my first attempt at making my own knife blades out of an old file. In this case, I'm using an old farrier rasp. This initial clip doesn't have any action footage, just finished stages of the project. It's nothing that hasn't been done before, just my interpretation and style. I'll post updates, hopefully with some actual process footage, as I progress..........stay sharp! John

Category:

Howto & Style

[MrJHAIII]

You can try A53, but it will likely not be easy to shape in a hardened state. It will also remain very brittle. Heating it up/Softening it would be the desired method for shaping, followed by re-heating, finish shaping, and annealing/stabilizing the steel (400 F for 2-3 hours.)

Good Luck!

[MrJHAIII]

Once hardened, it will still be pretty hot. I would let it cool enough to clean it off, and then put it in the oven, lying flat, at 400 F for about 2 - 3 hours. This will temper it, making it a little less brittle. Hope this helps!

[MrJHAIII]

When cooled off, try scratching it with a regular file.......you should be able to put deep scratches in it pretty easily at this point. If so, it should be "soft" enough to grind, cut, shape. When you achieve the desired shape and get it to about 85% finish (edge, thickness, filing details, etc.) you are ready to heat it up again using same process. Only this time, when you reach the appropriate heat, you will dip it (straight up and down!) in a bucket of water. This will harden it.

[MrJHAIII]

To soften the file, you have to heat it up until it's glowing reddish/orange.......if you have a magnet and can carefully touch it with the blade, and it doesn't stick (isn't magnetic), you have reached the appropriate heat (around 1500 F). Check to make sure it's not warped or bent. If so, you'll need to keep it hot until you can straighten it. If satisfied, lay it flat, someplace it won't burn anything (in some sand would be good), and let it cool to room temp on it's own.

[MrJHAIII]

sorry....that's "use them AS a pry-bar!"

[MrJHAIII]

They are only brittle if you use them are a pry-bar! Use them properly, and you won't have any issues. ;?)

[Squarerig]

Your voice resembles that of Woody Guthrie.

[1overthehillsfaraway]

One of the neat things about having a forge is that you can actually FORGE a blade and not have to cut it out and grind it down from a rasp.... those rasps are 1080 not 5160. They are softer than a file meant to cut metal.

[tamsims]

Really like this knife. How long is the blade and what is the overall length?

[ColdForgedCopper]

I used to make knives out of swedish steel files back in high school. I would heat 'em up red and let 'em cool down slowly in casting sand 2 times to soften 'em. then I would grind and file them smooth. then forge the edge, final shape grind and file. re heat to dark red and quick cool in water. rough polish and edge temper to staw colour with a torch. The result was one heavy duty bush wacking blade. other attempts made before this method resulted in easily broken brittle blades.

[anonomous53]

I am thinking about making one of these myself, buy the file I have bevels down in both sides to a pretty fine edge. Do you thinks that I could just grind it down with a grinding stone? Or do I still have to un harden the steel? The file is pretty old and it can be scratched by a hacksaw blade.

[TheNinjas223]

@elisiamarie ok thanks for the info.

[elisiamarie]

TheNinjas223.........When making them? Belt sander, Sand paper, and Steel Wool. When a finished blade becomes tarnished, light sand paper and steel wool. These blades need to be kept clean, and a light coating of oil while stored doesn't hurt. If concerned over oil contaminating meat while field dressing, you could always just use some cooking oil. They really won't tarnish bad as long as they are cleaned, dried, and stored in a low humidity environment.

[hifeyracer]

how was prison?.....does this one fit?....how long have u been a mule? lol