Hollow Hole Punch, Make Your Own

Created: October 22, 2023

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How to make your own Hollow Punches for making holes in soft materials like gasket material, etc.

Let's say you need to replace a carburetor gasket that has 4 screws holding the float bowl onto the main body. You already know how to make the gasket itself, but can't come up with a good way to make the little 3/16" diameter holes. Here's what to do: (takes longer to tell it than to do it)

Get a piece of round steel rod that's about 3" to 6" long. Ideally the diameter should be about 1/8" bigger than the hole you need, but it's okay if the rod is somewhat bigger than that. Drill a hole in the end of it that is the same diameter as the hole that you need in the gasket. A 1/4" deep hole is enough, but a little more is better, say 3/8". It's not critical.

Now to the grinder. Holding the part at an angle of about 60 degrees to the wheel, grind away material around the hole you just drilled.
(This will give you a cutting edge with about a 30 degree angle).
The objective here is to grind carefully to produce a sharp edge right at the edge of that hole, while keeping the edge fairly straight.

That's all there is to it. You have just made a custom hole punch, for soft materials like neoprene, gasket materials, leather, etc..

To use it. place the gasket on a block of fine grained wood or masonite, etc., set the punch over the spot for the hole and tap with a hammer. The punch-out will enter the hole and probably stay there, so the deeper the hole, the less often you have to dig the punch-outs out.

It's a good idea to practice a couple of holes the first time you do this, so you can see the effect of sharp edge on the gasket material. Toooo acute an edge and it can just fold up. It that happens, just go back to the grinder and produce a new, slightly duller, but stronger edge.

You can get fancier by honing the edge, but for a one time use, you can probably make several holes without problems.