To provide a screw driver which prevents the damage of other objects packed together with the screw driver by covering a driver stem having a sharp tip end when the screw driver is carried, and further which is convenient when an operator wants to temporarily separate his hand from the screw driver during its independent use.

A grip portion of the screw driver is formed as a U shape, and a sheath hole 4 is provided in an arm having no driver stem 6 so as to open at the end face of the arm. A pair of such screw drivers form a ring shape by inserting the driver stem of the one screw driver into the sheath hole of the other screw driver. Thus, the sharp tip ends are covered with each other and do not damage the other objects packed together with the screw divers. In addition, because of the ring shape, the screw drivers can be hung on a hook like a key holder, and further can be easily carried even when a bag, etc. cannot be carried. Further, because the screw driver has the U shape, it can be hung on a hook, etc. existing at hand even when the screw driver is independently used.