Diamond Blade Throwing Hatchet

Many winters ago, I was working a construction project and therefore used quite a few cement cutting diamond blades. Within the process of grinding away each blade I held onto the used blades for a future project. Then this winter they got me thinking, I’m a blade lover and decided, I now wanted to make a throwing hatchet and I had the perfect use for an old diamond blade.

NOTE: Because this is an unknown material it is not the best option for making a hatchet. Me,
myself was just looking to make a fun toy out of the material I had so it worked for that purpose. If you use a diamond blade or saw blade for a knife or hatchet just be aware that it might not hold up that great. For a fun toy or first try at a knife or a hatchet it would work decent enough and it would give you some practice.

Because this was a 230mm blade it would have to be a smaller sized hatchet.

I did some looking around to get an idea of a good shape for a hatchet head and then I drew my design onto the saw with a marker. I wanted to make it reach as far down the handle as possible.

Now that the pattern is marked out it is time to cut it out.

I used an angle grinder for this but a hacksaw with a lot of time would work as well. I've used a hacksaw for cutting out blades before. An angle grinder is a wonderful tool to have.

With the rough shape cut, it was now time to refine the shape.

I used a Flap grinder disk on my grinder belt sander for the outside shape and a Afile Engineering Hand file Dremel for the inside curves. You could use a belt sander and a Dremel if you have the tools, which would make it a lot easier.

With the shape now finalized, it is time to put the initial bevels onto the hatchet head.

Because of this I only ground the initial bevel. If I have to heat treat it then I don't want to finish the bevel until after the heat treat.

Because I am mounting this to a handle I needed to drill the holes for the bolts/pins that will hold the handle on the hatchet head. I wasn't sure if I'd be able to drill the holes without annealing the blade so I figured I'd see how it went. But it did drill. Which was a little concerning as this meant the material was not as hard as I would like for it to be able to hold an edge well. But we will fix that

Now that the head portion was fully shaped it was time to move on to a handle.

I had a piece of meranti from an old wooden door frame. Not the idealist wood for a hatchet handle, but it was the best I could find in my barn. Preferably a piece of maple would have worked wonderfully. But yet again this is just for fun, so as long the handle holds, it worked. I first outlined the portion of the head that would engage with the handle and then sketched the rest of the handle. Because of the smaller size of this head I kept the handle on the smaller size as well. I made sure there was enough material to hold on to and then shaped it to give it a nice hatchet handle shape.

Now that you have a pattern it is time to cut it out.

I always cut wide leaving some extra material around my sketch and then I'll sand to shape. I figure it is always easier to remove more material than to add material back.

Now that you have the rough shape of the handle it is time to cut the slot for the head to fit into.

I set the fence on the miter saw to cut it down the center and then I cut it down to the mark I made when I sketched out the handle shape. Depending on your blade thickness you may need to do a second cut or sand the slot to make it the same size as the material thickness.

Now to drill the matching holes in the handle.

I drilled the first hole and then used the hatchet head as a guide to drill the second hole. I used one of the bolts that I will use to hold it together to keep the first hole aligned.

I then inserted the blade in the slot and inserted both bolts into place and sanded down the handle with a flap grinder disk of wood so that it was the same width as the hatchet head.

It's now time to finalize the shape of the handle.

I cleaned up the shape and then rounded out all the edges to make it fit better when holding it. I started with 40 - 60 grit on my flap grinder disk to rough out the shape and then moved to 80 - 120 grit sandpaper to sand it down by hand.

Now that I need to heat treat the blade it is time to do that.

I just used a torch to bring the edges up to red hot and then quenched it in canola oil.

Because I didn't want it to be quite as high as 60HRC, I tempered it at 220 degrees Celsius for 1 hour.

Now that the blade is hard it is time to clean it up.

Because this was a diamond blade and I am making this to be a throwing hatchet I am not going to spend a ton of time making sure this has the absolutely best finish. Not to mention that the material is already pretty thin, I don't want to sand it any thinner if I can help it. I just sanded away the scale with fine paper and then used my hand sander to finish the bevels and sharpen it. This is as high of grit and because it's a throwing hatchet it doesn't even need to be that sharp.

With the head finished, it is time to mount it on the handle.

If I were to be making a knife, I would glue the handle along with potentially peening rivets as well. Because I will be throwing this there is an increased risk that the handle could break, and I don't want to have to deal with removing the glue to attach another handle to it, I will just be bolted with bolts & nuts without glue. Then all I would need to do is loosen the bolts & nuts and make a new handle to attach to it.

You can also use peened rivets instead of bolts & nuts.

{If you haven't peened rivets before all you need to do is cut the brass rod so that it sticks out
3mm from each side and then do lots of little hits with a ball peen hammer until the end widens so that the handle can't separate. Just be careful as you can widen the rivet too much and it can split the wood. And then you just grind down the rivet so that it is flush with the handle. Keep checking the fit as you grind and if it loosens up then you can hammer it some more.}

Now that it is almost complete it is time to apply the finish to the handle.

I just used a bit of varnish, you could use Danish oil or Linseed oil.

It is now complete. All that is left is to go and have fun with it.

Throwing a hatchet takes some practice but is a lot of fun. I used some Styrofoam as a target. I was also concerned about the steel being too brittle and breaking but the throws that didn't stick bounced across the concrete and the blade remained fine so that is a good sign. I plan on eventually making a target out of soft pine so that knives or hatchets will stick into it well.