by bill from nh » Wed Feb 17, 2016 9:25 pm
Hardened & knurled setscrews are both sold too. The best setscrews I've used were Bristol Spline setscrews. Cousins of the Torx screws, small sizes aren't manufactured anymore. You could torque those things down on a drill blank hard enough to put a 360 degree twist in an allen wrench. I used them while racing open class wing cars in the 70's.