Hole saw bits have to be the worst, especially the big ones, like a 3 inch. Hate to recall how many holes I've drilled over the decades with hole saw bits in 2 x 4 and 2 X 6 wall studs, overhead double top plates, etc. Drilling holes for 1 1/2, 2 and 3 inch pvc drain, waste and vent plumbing is nerve wracking...you know the wrist twister is coming at some point and you're just waiting for it. Also you can get the back of hand/knuckle/fingers raked across a protruding nail or screw point or wood sliver. Miracle I never broke a bone.