cobalt327
Plastic
- Joined
- Apr 27, 2016
I am enlarging 5/64” ID x 2” long mild steel tubes having no visible seam to 7/64” ID. I am using a very rudimentary method- a drill press spinning the bit 1750 rpm (I can go as high as 2600 rpm max) with the tubing held stationary in a Jacobs chuck. I am using a 135 degree cobalt bit and 5w 20 synthetic motor oil for lubrication, applied every pass. I am taking an average of 8 passes per tube, feeding “gently”. Each pass I back the bit out and clean the chips and reapply lube to the tube ID and the bit. Early in the hole, I am getting long strands that are ejected from the tube, later when the 1.4” long flutes are inside the tube, the chips are much smaller. I am getting around 40 pieces before I feel the bit dulling.
Should I increase the speed to 2600 rpm?
Is there a better lube that I can apply manually? How often should I apply it?
Would 118 degree bit be better? Would it work at all?
Thanks in advance for any help!
Should I increase the speed to 2600 rpm?
Is there a better lube that I can apply manually? How often should I apply it?
Would 118 degree bit be better? Would it work at all?
Thanks in advance for any help!