In June 2005, I was having problems because my little 12" Delta variable-speed drill press has a minimum speed of 500 rpm, which was a real problem, especially when countersinking.
I had found an interim solution for larger holes: Put the countersink in the hole and turn power on, releasing the downward pressure before the press gets up to speed.
This did not work with small holes, and the 1/4-inch severance countersink, working in 6061 aluminum, flooded with a water-based coolant. I would have thought that a small countersink would be OK at500 rpm, but the holes became ragged and misshapen.
Countersinking with a hand drill did work, making pretty holes, but yielded inaccurate countersinks because it's so hard to drill straight by hand.
I was busily tearing metal and hair when it occurred to me that tapping is an extreme kind of machining, and yet one can get clean threads, with the right lubricant. So I tried LPS Labs' "Tap-All". It worked, even at 500 rpm.
Haven't tried it in steel and/or for large holes yet.