07-21-2016, 09:49 AM
Your using the rest of the bolt as a guide is intriguing, but I suspect it is going to be darned hard to drill straight down through the bolt and stay perfectly centered. It's something a machine shop should be able to do for you though.
Alternatively, could you just drill out the bolt completely (leaving the threads if possible) and then use a thread chaser to remove the bits of bolt left in the threads?
Alternatively, could you just drill out the bolt completely (leaving the threads if possible) and then use a thread chaser to remove the bits of bolt left in the threads?