Blog
Best posts
About me
Shop
CAD Dojo

Party Puzzling
Hardbin
URL Canary
SCAMP CPU
Collapse OS docs
Seasonal.css
Stegoseed
Image Steganography
Mojibake Steganography
Chess Steganography
4x4 Chess Puzzle
Chess Clock
Anagram Deputy

This site is part of the webring: Tech Makers
«prev random next»

James Stanley

I made a knife out of a file

Sun 28 June 2015

Since making a little knife out of a hacksaw blade a few weeks ago, I've been working on a bigger knife made from a file.

I drew the outline of the knife on to the file, and ground it out. I was careful not to let the file get too hot as this can apparently ruin the hardening of the steel and keep it from holding an edge properly. I just kept a glass of water by the grinder to dip the steel in every few seconds.

The knife has what I believe is termed a "hollow grind". I cut a block of wood at an angle and clamped the steel to it. I them dragged the steel across the grinding wheel using the wood to keep it square, hence forming a hollow grind.

At this point the surface of the file was still a file, which is not at all helpful for a knife (perhaps a knife+file multitool? but that's another project). I used the belt sander attachment on my grinder to take the teeth off the file. I actually stopped a little short of completely removing the shape of the teeth as I like the look of it.

I used some more of the oak offcuts I have to make the handle. I tried to drill some holes through the tang to use pins to hold the handle on, but the steel is unfortunately too hard! I expected to have trouble drilling the holes but had no idea it would be this hard. I even heated the tang up to the point where it changed colour in an effort to ruin the hardening (who needs a hardened handle?) but to no avail. The only outcome of my efforts toward drilling holes was a blunted drill bit.

No matter, I simply epoxied the oak to the tang with no pins. Once the epoxy had dried, I shaped it on the belt sander. I removed the "table" from the belt sander so that the belt could flex a bit to help make the rounded edges. This worked better than expected.

Next I polished the blade a bit using a polishing wheel on my Dremel (but it could have done with a bit more polishing). I tried to sharpen the blade but I am still rubbish at it. The knife is sharp enough to get by but I wish I was able to sharpen knives better...

Finally I applied wax to the handle.

The main mistake with this knife is that the point of the blade is not quite a point due to the wooden blocks method I used to grind it. Ideally I would have kept the tangent of the edge of the blade parallel to the ground at the point of grinding, but I just kept the body of the blade parallel to the ground.

I'm pretty pleased with the result. More pictures here. I didn't take as many as I ought to have done.

If you like my blog, please consider subscribing to the RSS feed or the mailing list:

James Stanley - james@incoherency.co.uk | jesblogfnk2boep4.onion | [rss]