Old thread, but in cases someone arrives here with the same question . . . I know I did!
For SS Keggles:
I used a 7/8" step bit from harbor freight (2 for ~$15) and 18V Ryobi to drill out 8 holes for weldless SS fittings (bargainfittings.com). First measured for location and then hammered the point of a philips screwdriver to make a slight indent. Switched to a 3/8" standard bit to drill a pilot hole. Using the high-speed setting I easily cut through the SS, stopping every 5 seconds to spray WD40 for "cooling". Then I switched to the step bit. Using the same approach (drill, stop, cool), but at much lower speeds it took about 2 min/hole. You'll definitely need to be hold on tight as it binds a bit when it bites. I also noticed that as I got to the larger diameter steps I needed to reverse the drill. My drill just seemed to bite off more than it could chew on first cut. Reversing removed the burr, and then I continued cutting. The holes were surprisingly clean (no burrs) and looked great!