IRWIN 1899945 Impact Performance Series Screwdriver Insert Bit, T20 Torx, 1-Inch Built for maximum durability and long life with impact drivers Precision tip geometry delivers superior fitment, reducing stripping and cam-out Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output Black oxide finish resists corrosion and increases life of bit 1/4" quick-change shank is designed to work with impact drivers and reduces slipping in standard drill chucks