To be honest I've drilled so many holes I don't even look at the settings on my tools that much....it's all by sound.....I tune it by sound and by feel alot of times and depends on the tank as well, and how big of holes I'm drilling.....Usually I'm drilling 1 1/2" or bigger bulkheads.....I would say I probably run about 25,000rpms.....I use to have a dremel the basic one that was fantastic, and then upgraded to the Pro, and took over to a buddies house and cut about 4' of drywall and the thing burned up.......wouldn't even turn......Needless to say next morning back to Lowes, and traded for the Rotozip with alittle more juice.....I don't think I'd ever go back though.....Dremel does have more accessories though IMO....