Originally Posted by jebensch

Mildly tangential but:

I learned to *not* hold any metal parts with bare hands when drilling them. I had to drill out the hole of a tin escutcheon - meant for the cord of a pendant light to come through - to accommodate the suspending chain of a pot rack. Anyway, I held the edges of the tin firmly, and the second I pulled the trigger on my drill, the bit bit, spinning the tin and its very-sharp-at-high-speed edges across my thumb and forefinger. Then there was that terrible moment where time slows down as you stare at a gash knowing that you're about to see a lot of blood.

Gloves or clamps or both. The lesson has been very valuable carried over to bike work.