The shooting club I belong to uses aluminum clips to hold cardboard target backers to wooden target frames. The clips are made from soft aluminum roll flashing, and are held to the frames by a pair of aluminum nails. Over time, the frames & clips get shot up, and we have to keep building new frames & making more clips. I've made some jigs to help mass produce the clips. Part of the process is to drill a stack of the blanks to make holes for the nails. The jig I made has two 3/32" steel drill bushings for this purpose.
The problem is the drilling. Roll flashing is typical soft aluminum, and wants to stick to the drill & stick to itself. It also wants to fuse together rather than cut. I'd like to just be able to zip through a stack of 10 or more blanks, but if I'm in the least bit impatient, I end up welding the stack together at the holes. I also end up with stringy chips stuck in the drill flutes. To minimize mess, I'm doing this dry, with no cutting lube. It slows things down considerably if I have to keep peeling chips out of the drill flutes, and pry all the blanks apart at the end of the drilling process.
I started with some fast twist bits from McMaster Carr, on the theory that they would pull the chips out better. They have a bright finish, and I'm not convinced that they are any better than normal drill bits.
Rumor has it that black oxide finished will help prevent the chips sticking to the drill bit. I'm wondering if there is anything else special I should look for. Split points might be helpful, but I'm not sure anyone bothers for drill bits this small.
Ideas or suggestions would be appreciated. I don't mind spending a few bucks on fancy drill bits if it will speed up the process considerably.
Thanks!
Doug White