Originally Posted by
Andrew
I've been using sharpened brass tubing -- I wonder if a drill leaves a nick that eventually turns into a stress fracture.
I don't think so. When I drill plastic, I use by hand a larger drill bit to remove the burr around the hole, above and below. That should remove the "nick". Using a sharp, not worn bit helps cut a clean hole without much force. Also, I use a speed slow enough that the bit doesn't significantly heat the plastic. It should cut cleanly through with next to no force.