To me that seems about right on the speed, but even for the best super duper carbide drills, that seems like a lot of feed. The suggested feed is .016 per rev, thats seems like a heck of a lot for a 1/2" drill.
What kind of failure are you getting? Are you pecking? I wouldn't. If I had to guess, I would say that whatever damage you're getting is at the start of the hole. I don't spot either when drilling with carbide, unless I need a chamfer, but if I'm going to be pushing some high feed in the hole, I will start the hole at a low feed to avoid any deflection, this is probably more important on a forging that is probably not dead flat. |