PURPOSE: To provide sufficient fastening force without being excessively fastened by eliminating a loss in fastening force to the possible minimum level, providing strong fastening force by small rotation input, providing sufficient fastening force by manual operation, and effectively using reaction of a rotary tool.

CONSTITUTION: A flange ring 18 contacts with an installing object 42, rotation of a screw member 11 stops, and when put in a fastening state, rotation of an operation ring 12 is fed by a screw when a ball 13 rolls in screw grooves 25, 32 to press the flange ring 18 via a regulating ring 16 by a movement of the operation ring by this screw feed to fasten an installing object tool. Rotation of the screw feed of the operation ring 12 can be effectively transmitted to the flange ring 18 without losing torque of the operation ring 12 since frictional resistance becomes almost zero. Reaction when using the installing object is transmitted to the flange ring 18 to generate fastening directional relative rotation between the regulating ring 16 and the operation ring 12 until dry metal slips to increase mutual fastening force to be more effectively fastened.