Make Your Own Hook Knife Using an Old Metal Wrench

Here’s something anyone can make with a wrench: a circular hook knife. However, instead of using the hardware tool to pull or twist something into place, you’ll actually be breaking the metal down and turning it into something new.

The man behind The Small Workshop YouTube channel didn’t have his own forge, so he took an old metal wrench with a ring spanner and turned it into something new.

Majority of the work involves shaping that ring spanner. After chopping off the part of the wrench that makes it… well, a wrench, you’ll need a rotary tool to narrow down the circular metal. Doing so will render the wrench useless as a gripping tool, but it will make it that much closer to a cutting apparatus.

Once you’ve thinned out the metal, you’ll need to carve out some grooves so you can hold the knife more easily. Use a marker to plan out your cuts and employ an angle grinder to cut off that excess metal.

If you’ve thinned out the spanner enough, the metal should now be sharp enough to carve wood. Smoothen the inside with some P600-grit sandpaper before polishing it off!

Up until now, you’ve only been shaping one side of the knife. In order to fit the metal into a handle (in this case, an old filehandle), you’ll need to cut the wrench down to size and shorten the width with an angle grinder. If all goes well, you’ll have a metal hook knife that fits perfectly into your handle.

All that’s left to do now is carve out room inside your wooden handle (a drill seems to work just fine) and hammer the metal in. And there you go: a metal hook knife repurposed from a perfectly good metal wrench.

If you won’t get anxiety from having an incomplete wrench set, this is totally a viable way of making new tools without melting any metal. For everyone else, however, it might be best to just save your wrenches and buy your own hook knife instead.

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