PURPOSE: To enable the use of a single driver in a way to select it into a driver for a plus thread use and that for a minus thread use by a method wherein a blade for a plus thread use is mounted to the tip of a pair of slide parts, the slide parts are selectively slid to the root and the tip of a shaft by threadedly joining a ring with the male screw of the shaft, the slide parts are securely engaged with the ring.

CONSTITUTION: A pair of slide parts 4 are slid toward the grib 2 side along a groove part (a) formed in a shaft 1 by means of a ring 3. The female screw of the ring 3 is threadedly joined with a male screw formed on the root of the shaft 1, the slide parts 4 are secured to the grip 2 side to form a drive for a minus thread. When the driver is selected for a plus thread use, the joint is released, the slide parts 4 are slid to the minus blade (b) side along the groove part (a) by means of the ring 3, and blades (g) for a plus use of the slide parts 4 are positioned in line with the minus blade (b). With this state, the ring 3 is threadely joined with a male screw (c) formed on the tip of the shaft 1, the slide parts 4 are secured on the tip side to form a driver for a plus thread use.