I have been trying to figure out how to drill holes through round 1" ERW (11 gauge). Each time I drill, the hole that comes out the far
side of the tube has 'ridges' (I'm not sure of the term) when the bit exits. I've included some photos of the exit hole.
I am using a drill press. I apply a good amount of drilling coolant/oil and clean off the drilling shavings every 15 or 20 seconds of drilling.
I tried to delete the last photo (on the right). That is the inside of the entrance hole and it didn't get 'cleaned' out. I'll save that issue for later...if I can figure out the exit hole problem.
Would you have any suggestions on how can improve this so the outside of the exit hole is smooth?
Thanks.
side of the tube has 'ridges' (I'm not sure of the term) when the bit exits. I've included some photos of the exit hole.
I am using a drill press. I apply a good amount of drilling coolant/oil and clean off the drilling shavings every 15 or 20 seconds of drilling.
I tried to delete the last photo (on the right). That is the inside of the entrance hole and it didn't get 'cleaned' out. I'll save that issue for later...if I can figure out the exit hole problem.
Would you have any suggestions on how can improve this so the outside of the exit hole is smooth?
Thanks.