Features and Benefits: Designed to remove broken studs bolts socket screws and fittings Aggressive left hand spiral design for extra gripping power Spiral flutes are designed to embed themselves deeper into the metal as you turn the tool so as the fastener resistance increases the extractor s grip increases Extractor size and recommended drill bit size are etched on each tool Recommended tap wrench: TR-88; use drill size: 7/64 removes bolts and screws: 5/32 - 7/32 4 mm - 6 mm No. 6 - No. 12.