A screwdriver bit is a tool for driving screws and one that can be fitted to most drilling power tools. All screws have a head with a contour such that an appropriate screwdriver tip can be engaged in it in such a way that the application of sufficient torque to the screwdriver will cause the screw to rotate.Details: Manufactured with heavy-duty, cold-forged, high grade steel to withstand high torque output Forged bit for superior fitment which reduces stripping and increases life of bit 3X Built for maximum durability and long life with impact drivers Specifications: UPC: 40028877525295 Manufacturer Part #: IWAF31PH2B25 Product Type: Phillips Insert Bit Bit Length: 1" Fastener Size: #2 Hex Shank Size: 1/4" Fastener Material: Steel End Type: Single End Finish: Corrosion Coated