Aggressive left-hand spiral tears into fastener materials while enhancing extractor grip. Torque-enhancing tapered flute embeds itself more easily with each turn. Clear, permanent extractor size and recommended drill bit stamps simplify tool selection. When used in conjunction with an appropriate drill bit (sold separately), spiral-flute, high-carbon-steel extractor makes removing broken studs, bolts, socket screws and fittings easy. Head Type: Spiral-Flute.