Cutting Holes In Sheetmatal

[PixMan]

I've done up to 4" holes in (somewhat thinner) sheet metal just the way DaveH describes. The orbital motion makes a slightly bigger hole but solves the biggest problem: Too many teeth in the cut at once stalls the drill motor or breaks your wrist. I use high quality Lenox Bi-Metal (HSS teeth) saws as my Metabo 1/2" drill doesn't go quite slow enough for a cheap high carbon steel one.