Up to 50 times more robust than a Bosch 2607001528 Extra Hard Bit. Do you need Robertson screwdriver bits for driving screws? Bits that last long and perform well in demanding applications? Then the PRO R Impact Bits are the right choice. They are designed for strength and resistance to high torque. The PRO R Impact Bits are an excellent option for installers looking for durable screwdriver bits for tough jobs. The bits are made from heat-treated, modified steel for outstanding stability and resistance to high torque. Their torsion zone absorbs the torque stress at the tip of the bits to ensure they do not break. They feature color-coded rings that indicate the head type and laser markings to assist you in selecting the required size. Impact-resistant 1/4-inch hex shank for use with impact drivers and drill drivers.