This set of hex bits for impact drivers are ideal for removing and replacing large hex fasteners in automotive and large machines such as sensor plugs. The chrome molybdenum construction of these hex bits provides the strength to endure high-force impacts. Features include a black phosphate coating to resist rust, making this a great hex driver set for mechanics and machinists. Designed to stand up to the demands of high-force impact drivers Chrome-moly construction Black phosphate finish