I have an Industrial Hobbies CNC mill. Just recently I needed to drill several 7/32 holes in 1020 steel. I ran it at 1600 rpm with 3 ipm speed, with a stub drill bit in a keyless chuck. I like the keyless chuck because my stub drill bits bottom out in the chuck, maintaining my tool offsets. I manually tightened the bit as hard as I could. In the first hole at about 3/16 deep, my drill bit stopped rotating, slipping in the chuck. Needless to say, I hit the E-Stop button real fast. Just thought I would see if anyone on this forum has experienced this problem before and what might have caused the slippage.