I use an old Black and Decker jig saw to cut out metal when it is too late at night to use the metal chop saw. It goes through blades pretty fast though, and that can get expensive. Even when you keep shortening the blade so you get a fresh set of teeth...

I realized I could make my own blades out of a hacksaw blade. This is nice because the kerf is smaller, so it cuts faster the

Step 1: Outline and Cut Hacksaw Blade

This is so easy, all you have to do is put a jigsaw blade on top of the hack saw blade, line up the front edges, and make sure the teeth are pointed the same direction.

Use a Sharpie to mark the edges around the blade.

Use Tin Snips / Metal Shears to cut out the blade (hacksaw blades aren't made of the best steel, so this is easy to do).

Use a belt sander or file to remove teeth where the blade goes into the jig saw.

Viola! An awesome blade for cutting metal for your jig saw.