How to cut a hole in steel sheet for control panel?

[timsatari]

Hi all - I guess I need some help with metalworking 101 here! I've got my original arcade cabinet control panel that is steel (about 4mm thick) with a plastic (plexiglass?) sheet on top of this. I need to add some button holes, what's the easiest method to do this?
Many thanks
tim.

[Ken Layton]

Hole punching has been discussed to death. Get either a Greenlee chassis (a.k.a. knockout) punch in the 1-1/8" size (same size that electricians use for 3/4" conduit holes) or a 1-1/8" hole saw for metal panels. Both of these are available at Home Depot.

The Greenlee punch provides the cleanest, smoothest hole. It may also be marked as a 28.2 mm diameter punch.

[Stingray]

The Greenlee punches look like a great tool to own, but since I don't have any yet I'm still using a hole saw. I usually end up with a fairly rough edged hole which I smooth out with a file. A punch would be so much quicker.

-S