Special step drill for screw holes, HSS step drill for burr-free drilling of through holes for screw hole pull screws M8 (3/8) -M10 (7/16) -M12-M16-3/4-M20 in material up to 4 mm thick. Suitable for use in hand and pillar drills, a total of 9 drilling steps, mounting shaft (10 mm diameter) with 3 driving surfaces prevents slipping in the drill chuck.
