Quickly and easily removes most damaged screws such as Hex, Phillips, Torx, and Square Drive; Bolts No. 4-10 (5mm) and 1/4" dia. from wood, plastic or metal. Two-step, screw and bolt extractor in one tool, extracts broken bolts and screws fast; use in variable speed reversible drill. Precision engineered for multiple extractions and maximum performance. The self centering drill tip prevents wondering and walking, so it works on jagged or uneven rough breaks. While the serrated extracting end of the tools results in greater torque for those hard to remove bolts and screws, No grinding or center punching required. Drills up to Grade 8 and 10.9 class fasteners.