Just A Little Nibble

So I have a project coming up where I need to fit something into a square hole. Getting the thing in the hole isn't the hard part, though, it's making the hole in the first place in a piece of sheet metal.

You see, if you want to make a small round hole, you can use a step drill bit. If you want to make a large square hole, you can use shears. But a small square hole? That requires a different approach.

I have chosen the approach of using a nibbler.

The way this works is, as its name might suggest, by nibbling its way through the metal, using this square edged punch thats drawn down into the face of the tool.

So let's give it a test run on a small piece of scrap, just a bit of 26ga galvanized left over from a previous project. The first step is to drill a 3/8" hole so that the die of the nibbler can fit through.

And yes, installing this toggle switch in a piece of sheet metal is the actual task I'll be aiming to do later. It requires a 1/2" by 3/4" rectangular hole, which I scribe out on some blue sharpie.

The scrap itself isn't perfectly square, so ignore that it looks a little wonky on the top edge.

Anyway, let's give it a nibble.

Well that was refreshingly easy. The nibbler went through it just like butter.

Also pro tip: if you've never used one of these before you might think that the tool should be inserted from the top, but it is way, way easier to guide the cut if you insert it from the bottom, so try to do that whenever possible.

After making a full lap, the hole is pretty close to the marks, but I did miss them here and there by just a smidge.

Rather than try to shave off the last little bits with the nibbler, I'll instead use some files to take the cut to the line. It'll also give me a chance to deburr the hole, which can be a little sharp on the backside.

And a test fit shows that the switch snaps right in.

And everything looks good from the back too.

Well, I'll call that a success.