i recently got a frameset back from the powdercoater's which i've been building up. i tried threading an M5 bolt into the fork-monted fender stay threaded eyelet, but the threads hadn't been properly chased. the bolt threaded in about half-way before it started to feel tight. i didn't think i was applying too much torque, but it eventually snapped! it was a stainless steel bolt. i'm guessing i have no option but to drill it out.
what is the best approach/what is the best type of drill bit to get this sucker out?? i need to preserve the integrity of the eyelet threads, and i don't want to damage the powdercoating around the eyelet. this is a reynolds 531 fork (from a raleigh competition, link in signature to pics) and i *really* don't want to damage it. i know i will have to be careful. i've been toying with several options: first, drill a small hole in the center of the bolt and thread a self-tapping screw into it from behind (since the eyelet is open in the back!). hopefully the clockwise threading of the self-tapping screw into the broken bolt will drive the bolt to thread back out the same way it threaded in. second option: use a larger drill bit closer to the diameter of the bolt, causing it to more or less disintegrate inside the eyelet. there is more risk of damaging the eyelet threads this way, but the first option may not work.
what are everyone's thoughts? any other ideas? any special tools that i should consider?