Making a DIY Knife

When I was in Japan a a year or two back I bought a kit for making your own folding knife from the big DIY department store Tokyu Hands. Since then I’ve been too busy with other stuff but now I finally had time to assemble it and I thought it might be fun to show how I made it.

The kit consists of two handle parts, a blade, two sets of screws, four washers, a stop pin, two pieces of sand paper, a small tool and the instructions manual. They come in different versions but I got the one where the handle parts are plain rectangles so you can shape the handle yourself.

Step 1: Translate the instructions manual to English to see that I’m not missing any key information then assemble the parts to see how they fit together.

Step 2: Design the shape of the handle and make a template. The instructions manual has some template spaces where you can see the original size of the handles, placement of the holes and so on. I used this to draw the shape I wanted then cut it out. I realized a bit late that it’s useful to take a copy of the manual so you can retry if you’re not happy with your design. Eventually I ended up with four slightly different designs. After carefully choosing the one I liked the most I transfered it to the handle pieces.

Step 3: I used a saw to rough cut the handle shape. In order for the two halves to match up, I kept them screwed together during the process but without the blade. I don’t have any saw that’s good for cutting curved shapes, so I had to make a lot of little cuts and break off the pieces as I went along.

Step 4: Sanding the handles down to the template line. Barring the use of a belt sander I think the best way to do it would be to use a set of files. However, I only own a round file and I didn’t want to buy any new tools, so for the most part I had to make do with some 60 grit sandpaper.

Step 5: I was happy with the overall shape but I wanted to round off the edges to make it more comfortable in the hand. Normally this would mean more sanding but I happened to have a set of wood carving knives that I bought for some reason but never used. I decided to try using those. It took a little while to get the technique right and learn which knives to use for which cuts but in the end I think it worked really well.

Step 6: After carving the handle was a little bit rough so I had to do another round of sanding to make it smooth. I did most of the work with the 60 grit paper then did a couple of quick passes with 120 grit and 240 grit that was included in the kit. The result was really nice.

Step 7: I wanted to give the handle a nicer surface than just the plain wood. I thought a while about what to use until I remembered we had some furniture wax at home so I gave that a try. Honestly it didn’t really do much except give the surface a slightly waxy feel. It might have been better to invest in some proper oil or clear coat paint. We’ll see how this holds up in the future.

Step 8: I noticed that the back corner of the blade was poking out a tiny little bit when the knife was closed. Not so much it would actually cut me but enough to make me want to do something about it. Luckily I had a set of diamond coated files that I had worked well for a few similar knife modifications, so I grabbed those and set to work.

Step 9: With all the parts finished it was time for final assembly.

I have to say I’m very pleased with the result. The knife looks really good and it feels good in the hand too. The blade shape isn’t ideal, I think it’s a bit too upswept but there’s nothing I can do about that. I think I did a really good job making the handle especially given the limited set of tools at my disposal. This was a fun little project so if you are in Tokyu Hands I would recommend picking up one of these little kits.