Don't know what anyone else uses, but I ran down to the local hardware store yesterday because I needed to cut a hole in the RF deck chassis for my 1625 clamp tube socket so I could recess the base below it. I found some DeWALT hole cutters and the 1 3/8" size worked perfect and the 1 1/4" cutter is the right size for 8-pin octal sockets if you just want to mount sockets and not recess them. I think I remember there were hole punch kits around years ago, but I always used hole saws to do it, but they had more jagged teeth and took forever especially if you were cutting through thick panels and not thin chassis material. These DeWALTs have very fine teeth and it only took about 3 turns of the drill to cut through. If you are trying to add holes in something that is already built then I'm not sure using punch kits would be a good idea. These DeWALT's would be the solution, I think.