Hanson 52205 Screw Ext Multi Spline 1/4, for Tap Die Extraction Screw extractor set is designed to remove broken studs, bolts, socket screws and fittings Screw extractors are ideal for high-torque applications Each IRWIN screw extractor has an aggressive left-hand spiral design for extra gripping power 1/4-inch recommended drill bit diameter 1/2" hex head and 7/16" bolt diameter