IBX1441 Features: * Designed to remove broken studs, bolts, socket screws and fittings for high torque applications * Aggressive left hand spiral design for extra gripping power * Hex head size: 1/2" * Bolt diameter: 1/4" * Recommended drill bit diameter: 5/32" * Hex Head Multi-Spline Screw Extractor - 5/32"""" Warranty: * Lifetime warranty does not cover abuse