Patent attributes
A screwdriver bit is revealed. The screwdriver bit includes a driving portion, a narrow neck portion integrated with and extended from the driving portion, and a working segment integrated with and extended from the narrow neck portion. The narrow neck portion consists of a connection portion, a first tapered transition, and a second tapered transition. The first tapered transition is an arc taper and the second tapered transition is a straight taper. When the screwdriver bit is driven by a power tool and is rotated at high speed, the torsional stress generated is dispersed by the first tapered transition while the second tapered transition is used to reduce torsional stress of the narrow neck portion. Thus the wearing of the screwdriver bit is effectively reduced.