Designed to remove broken studs, bolts, socket screws, and fittings, the IRWIN HANSON EX-5 Screw Extractor and 19/64" Drill Bit Set, features an aggressive left hand design for extra gripping power. Spiral flutes embed themselves deeper into the metal as the tool is turned so grip increases as resistance increases. Crafted of high speed steel, the extractor size and recommended drill bit size are etched onto each tool.