Patent attributes
The driver bit according to the present invention includes: a tip on which a cross blade is formed; a torque transmitting part having a polygonal outer circumference; and a locking groove which extends in the circumferential direction between the tip and the torque transmitting part and into which locking balls enter, wherein the tip has four blade forming grooves forming the cross blade, the blade forming grooves are continuous with the locking groove, and the blade forming grooves are arranged so that the blade forming grooves have bottom parts, at which they are connected with the locking groove, located inwardly of the outer circumference of the torque transmitting part, and the center lines are displaced from a line connecting the shaft center with vertex positions of the polygonal outer circumference and a line connecting the shaft center with center positions of sides of the polygonal outer circumference.
