Universal Use - The Extra-Hard Screwdriver Bit Set, 35-Piece is a good choice for universal use. This complete set contains accessories for important drilling and screw-driving applications. The screwdriver bits are composed of S2 Modified Steel and an optimised heat treatment process, which provides an extra-hard quality that delivers a strong performance for all tasks. They also feature a tapered torsion zone that easily handles torque peaks by absorbing force and vibrations. All bits are colour-coded for quick viewing and identification of the appropriate bit type. Furthermore, the set contains precision-ground drill bits made of HSS (high-speed steel), which enable a fast drilling rate in metal and plastics. They have a 1/4-inch external hex shank for use with screwdrivers and drill drivers. It has a 1/4-inch external hex shank and is intended for universal screw-driving with screwdrivers and drill drivers. The Extra Hard Screwdriver Bit Set, 35-Piece comes in a practical and robus