Century Drill and Tool 73414 Spiral Flute Screw Extractor Set, 6 Piece Spiral screw extractors are used when a screw or bolt has broken off while still in the fastening hole 6 Piece set includes NO 1, NO 2, NO 3, NO 4, NO 5 and NO 6 screw extractors. Easily removes 3/32-Inch to 7/8-Inch broken bolts and screws Made of hardened tempered alloy steel