It has a 1/4-inch external hex shank and is intended for universal screw-driving with screwdrivers and drill drivers. This Extra Hard Screwdriver Bit is a good choice for universal use. All tasks are achievable thanks to the bits S2 Modified Steel and an optimised heat treatment process resulting in extra-hard quality, enabling adequate performance in all tasks. The bits tapered torsion zone copes easily with torque peaks as it absorbs force and vibrations when screw-driving and thus fulfilling all tasks.