The Bosch 12 Piece Extra Hard Screwdriver Bit Set is a versatile collection of 25mm bits designed for universal screw-driving with screwdrivers and drill drivers across a wide range of applications. Each bit is manufactured from S2 Modified Steel and subjected to an optimised heat treatment process, resulting in extra-hard construction that delivers reliable performance across all common screw-driving tasks. The 1/4" external hex shank ensures a strong, secure connection with maximum torque transmission in both three-jaw chucks and 1/4" internal hex tool holders. A tapered torsion zone is built into each bit to absorb torque peaks, force, and vibrations during use. This helps protect both the bit and the fastener, making the set equally suited to controlled finish work and more demanding power driver applications. The set covers the most frequently used bit types across trade and site work, including Phillips, Pozi, and Torx profiles in a comprehensive range of sizes. Features and Benefits: • S2 Modified Steel construction with optimised heat treatment for extra-hard, long-lasting performance • Tapered torsion zone absorbs torque peaks, force, and vibration during screw-driving • 1/4" external hex shank for secure, high-torque connection in chucks and hex tool holders • 12-piece set covering PH, PZ, and Torx profiles for versatile, universal use Specifications: Bit Length: 25mm Net Weight: 0.135kg Contents: PH1, PH2, PH3, PZ1, PZ2, PZ3, T10, T15, T20, T25, T30