All of us want our tools to be as sharp as possible so we can do our best work. One of my pet peeves is punches, especially rotary ones, that won’t cut. Even the best tools will get dull over time with use. 40 years ago, we could get new tips or a new rotary punch and even the cheapest ones would cut well by today’s standards. About 25 or 30 years ago I bought a new super-duper high dollar professional quality one. Even back then, the tips were not sharp and wouldn’t cut leather right. I set that one aside and forgot about it. These days, it’s hard to find one at any price that cuts properly, even the replacement tip sets. In need of a sharp punch. I could buy a new one but if they were crap 30 years ago, they’re not going to be better now. I decided to sharpen the tips in the one I have.
I may have mentioned this in another thread but I’m putting this here so others will know how I sharpen them.
To use as a holder to sharpen the tips, the handle from my Tandy 3003-00 Mini Punch Set worked great. The thread size is the same as the rotary punch tips so I got to work.
To hold the tips, I chucked the handle in my hand drill.
While running the drill, I lightly touched the tips against my grey-green extra-fine grit CRATEX wheel at an oblique angle, being careful to not heat them. Also I didn’t want to take too much material off.
Then I did the same on the leather polishing wheel on my knife grinder using red jeweler’s rouge. That wheel rotates upward so the tip is dragging on it, not digging in.
You can tell when you have the tip sharp enough when it will not slip off your thumbnail when held at a very low angle.
I did this for all 6 tips and when done, they all cut effortlessly, as good as any punches I’ve ever used. When I first got the set of punches I found that the thread size on the tips for my Sargent & Co. parallel-jaw rotary punch were close enough to work in the Tandy handle so I sharpened those. Now, having sharpened both, I have two very sharp rotary punches and am pleased with the way they work.
If you don’t have a grinder with a CRATEX wheel and a low RPM knife grinder, get creative but don’t use a normal grinding wheel or you may wind up with tips that are too short or ground lopsided and still won’t cut right. You might be able to do the same thing by dragging the tip across a stone while turning in the drill. Then following that with a piece of leather with your polishing compound on it. I hope this gives some direction to others with the same dull rotary punches.
