A bolt or screw extractor tool is used to remove the most stubborn and challenging fasteners, especially those who suffer from a badly damaged head. Headless screws cannot be removed without damaging the surrounding surface and this is where stud extractors can come in handy. These tools are usually sold in a set and they come equipped with a drill-like device called a burnisher. This device is used to make a hole in the stripped screw or bolt. The second component is a reverse bit that is tailormade for the drilled hole and so it is used to bite into the screw and pull it out with ease. This dual feature was designed to work with a powered screwdriver or drill. Screw extractors come in two shapes. The well known and trademarked easy out shape is that of a spiral flute and the other one is shaped like a straight flute.