broken exhaust stud removal

Depending on how much patience you have and if you drilled the hole in the middle of the stud....you can keep drilling larger and larger until all that will be left are the threads of the stud. Once you get close to the threads you can get a very small center punch and start breaking the threads out of the hole by pushing them to the inside. A pick/scribe also helps to get the pieces out of the hole. I'm a machinist and I have done this many times with broken studs/bolts/screws. It takes patience and care.

Treblig