[sweeper]

I have not had this particular incident happen to me-yet, but I have broken many bolts and one method that works well (depending on the surrounding metal/material and flammables) is to weld a nut onto the broken bolt and back it out.

In this situation the the bolt (or whats left of it) is probably not seized- so the need to get the bolt real hot is not important. The method should still work just by tacking a nut onto the sheared remains of the bolt.

I use needle nose vice grips and a nut small enough that the hole will not overhang the bolt- clean the area with a non-flammable and wire brush- hold the nut over the bolt and tack it in place (two people may make the job easier) while holding it- position the nut so you can give it a partial turn without taking the vice grips off- take off the vice grips and finish with a ratchet- never use your bare hands....or you can but you will only do it once.

Just did it the other day on a water pump bolt on my BMW- took like 2 minutes.