Ah, bolt extractor, not stud extractor. Like a socket that you bash over the outside of a bolt head and as you turn they tighten on the outside. Slightly less risky. I’ve used them on broken Jag wheel nuts to good effect.NO, No , No, NO, No . . .
Why would seized in, stuck, won't rotate, not moving bolt now suddenly come out with a smaller diameter, brittle, ready to snap as soon as you look at it extractor jammed in it?