Something that worked for me...after the holes are drilled and heat treatment done. My 1/8" holes were just too tight for mosaic pins to go in. There was no way I was going to be able to enlarge the hole that tiny amount with a drill bit.
I used a diamond coated die grinder bit to enlarge holes a smidgen. I set the bit in the chuck on the drill press and worked it in a circular motion a few times around and the pins slipped through.
Where there's a will there's a way. Perhaps not the best way though.
Dan