Making a Machete from Scrap Steel

The machete is finished, testing done, and video posted. A little talk about the process.

I finally finished grinding the edge on my new steel wood chopper the other day and put it through the paces. It’s refreshing to create something that works this good using a pretty minimal tool set, and I’m super pleased with the result. She may not have it all in the looks department, but where it comes down to getting work done, she shines with functionality.

The story begins at my day-job. I was chopping up bits of scrap steel for the recycling bin and came across a chunk that I thought would make a decent machete. This is basically rolled sheet metal and not of much value for many things, especially in small pieces, but machetes (at least the good ones) tend to be cheap implements fashioned from simple steels.

In my surveying years, I spent a lot of time in the woods working with these tools, and consider them pretty indispensable. They won’t harvest firewood like an axe, and they aren’t the best for carving or other fine tasks reserved for small knives, but their functionality runs that wide range. I’ve sliced through six-inch pine trunks with them, as well as whittling little sticks to a point or for some other purpose. I’ve even chopped small bits of firewood and kindling with them. I’ve also used them for splitting and reeving wood, as well as a substitute for a draw knife.

And my favorites have always been the “cheap” variety, usually found in a five or ten dollar bin at the hardware store. The thin, flexible steel seems to perform best for their chief duty: clearing trails and brush.

The Start

I began with a blank piece about 30 inches long and 4 inches wide. I don’t know the type of steel, but it was 3/32 of an inch thick and seemed up to the task. I figured I would give it a shot. I spent some time devising a pattern that would suit my needs and did a little video on it here.

I started with a basic design, where the body of the blade starts a touch wider than the handle and widens toward the tip until the edge swoops to meet the back at the point. To clear brush or cut cane effectively, it’s to the users advantage that the blade is weighted more at the end as it helps to “pull” the edge through tough cuts. I wanted to take this a step farther, where there would be a big swell at the end to keep the balance point as far out as possible while still being manageable. I also shaped it such that the swollen edge is arranged similar to that of an axe: forward of the line of the handle.

I also wanted a forward cant to the overall edge, so from the handle, the blade curves forward immediately and then goes fairly straight until reaching the large curve near the tip. I also opted to have a pretty wide radius on that curve and added a drop point to finish the edge abruptly. I swelled the back in the same area to get all that weight at the end, and it’s also wide enough to grip comfortable with my off hand for use as a draw knife (debarking and that sort of thing).

The pattern could be cleaner, but it worked out pretty well. Here’s a picture of the finished blade showing that profile.

Another advantage to the somewhat narrow point was to increase the length over my regular machetes without adding too much extra weight to the design, and it allows the edge to be highly functional, even to the tip. The little point behind the scales simply looked cool and worked with the shape of the steel that I had.

Making the Blade

I used a hand-held jigsaw with a metal-cutting blade to carve the pattern. The process was pretty quick and effortless. I salvaged some scrap walnut from the burn pile and split it down into a pair of blanks, which were further carved and sanded, to make the scales. I drilled two holes through the metal blank and scales with a cordless drill, and in each went a nut and short bolt from the hardware store.

Then came the edge. It was shaped with a file, though a belt sander would have been much faster. I also found that clamping the metal down before working make the material removal go far faster. I suppose I’ve never done a side-by-side comparison before, but suffice to say I will be clamping everything that needs heavy filing from now on. You could use a bench vice, but I simply used some C-clamps and the edge of a table.

I filed the primary bevel at the same angle I would use to sharpen my thinner machete blades. I didn’t really think about measuring the angle ahead of time, but I just did some quick math on it, and the bevel works out to around 20 degrees at the point. Quite skinny for soft steel, but I always cut a secondary edge right at the tip with a much steeper filing angle, which I have no way of measuring. I would guess 30-35 degrees. Doing this keeps the metal behind the edge from getting too thin.

If the edge is too narrow, the steel basically acts like a foil, and can be damaged easily while cutting. I experienced this while trying to chop a seasoned log with it, and had to peen the edge back into shape with a couple of sledge hammers, but for everything else it worked, including splitting firewood!

As I’ve said, I’m super happy with the result. She’s not the prettiest knife in the world, but after a few rounds of testing her out she has performed admirably for any work I’ll request of her. She cuts cleanly through more than an inch-thick pine bough, so that should be plenty of might to overpower prickly brambles and little saplings with ease. The blade profile worked out perfectly, and she cuts everything in her reach. Couldn’t ask for more from this humble blade, and it’s already replaced the others as my go-to machete. I might even fashion a sheath for it at some point 😛

The followup video can be found here.

P.S. I haven’t been updating the video page lately. I’ve been doing a lot of filming so I think it will fill up far too quickly. Might be better to follow me on YouTube if you want to stay updated on those.

Thanks for dropping in. If there’s anything else you want to know about this project, just drop me a comment.

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