But at this point, with pretty much all of my bolt heads unsuitable for Torx bits, I figured it couldn’t hurt to try. A fastener in wood with a sheared head, say. How it works: Screw extractors are really meant, I think, for less severe situations. Since the thread cutter can’t keep going in, it pulls the fastener out. As the taper widens, the threads bite into the freshly drilled divot on the head of the fastener. Then you flip the bit, and the other end is a tapered thread cutter. You use it in the reverse direction to ream out the head of the screw. How it works: The one I used was Grabit, and it’s pretty simple.
