PURPOSE: To provide a drive bit generating wedging effect between the drive bit and a fastener, for holding the fastener with the drive bit before the fastener is fastened with a workpiece.

CONSTITUTION: A drive bit or a driver for fastening a fastener 12 with a workpiece is provided with a multilobular shaped engaging part 14 engaging with a complementary multilobular shaped part of the fastener, both sides of a linear projection 24 are divided with recessed grooves 26, the each linear projection is provided with a driving side wall 32 and a trailing tapered side wall 34, and the driving side walls are constituted so as to contact with complementary multilobular shaped grooves 30 or the socket 18 of the fastener 12, for applying torque to the fastener. Meanwhile, the trailing tapered side wall 34 is wedgingly engaged with the complementary multilobular shaped groove and linear projection at a point, when the driver or the drive bit is engaged with the groove of the fastener.