Speaking of anything from an 8/32 screw to a 3/4" bolt. How do you do it? I'm on a job where we had a heck of a time getting a 3/8" bolt out of a tapped flange. My usual procedure is to heat the bolt up red hot and tap on it with a hammer while heating it, let it cool down, and soak it with a penetrant like CRC Screwloose. When it cools down, I get on it with some vise-grips, and it usually comes out without much effort.
On this bolt, we drilled the center and tried two different kinds of screw extractors. Broke off both of them inside the bolt. Had to use a dremel tool with a tungsten carbide bit to grind out the screw extractors, then drill and re-tap the hole. What a pain in the azz!
Another one we had trouble with was a little 8/32 screw holding a small terminal plate. The screw broke off, and I went to drill it out with a cobalt bit. I broke the bit in the hole. Had to drill that bit out with another one and re-tap the hole.
Anyways, I was just curious what sort of tactics the rest of you are emplying when you encounter a rusted/seized/broken bolt. I bought a set of Lisle screw/bolt/stud extractors today, and I was also wondering if anyone here has ever used them with any success???