Our EZ-Outs, or "screw extractors", are made to extract broken screws, bolts, threaded parts, and pipe. A hole is drilled in the broken part with a left-hand drill bit, the extractor is inserted in the hole, and then the extractor is turned counterclockwise with a wrench. This allows the broken piece to be backed out of the hole without damaging the internal threads. This set contains both ez-outs and the corresponding left-hand drill bits. It contains ez-out sizes #1-#5 and left-hand drill bit sizes 3/32", 1/8", 3/16", 1/4", and 5/16". Made from high carbon steel.