- GRAPHITE impact bits type PZ1/2/3, with a total length of 50 mm, are heavy duty bits designed for heavier work with high torques using screwdrivers or impact drivers. Made of high-quality S2 steel, which is characterized by increased flexibility and resistance to mechanical damage. The torsion zone, rotating under the influence of high torque, reduces the transmission of force, which makes the bit more resistant to breakage, and its service life is extended several times.