- Joined
- Feb 15, 2015
- Messages
- 65
I need to manually drill a 0.125 diameter hole 2 inches deep in 304 free machining stainless. I'm using a mini mill. I drilled with a center drill about .250 deep to make sure the drill started true. I then used a jobber length solid carbide drill, peck drilling roughly 0.100 per peck with cutting oil. I withdrew the drill every two or three pecks and added oil into the hole. The drill snapped at the top of the flutes at the same depth of the flutes. I kept RPM low, about 1500. Max machine RPM is a bit below 4000. What am I doing wrong?