Axial-force-detecting fastening tool, bolt, and method of manufacturing the bolt

摘要

An axial-force-detective fastening tool fastens a nut to a bolt, and at the same time, detects an axial force acting on the bolt. This tool has improved durability and workability. The tool has a socket body (5) rotatably supported with a tool body (3) and having a nut receiver (19). The socket body turns a nut received in the nut receiver around an axis of the socket body, to fasten the nut to a bolt. A driver (9) is installed in the tool body, to rotate the socket body. An ultrasonic sensor (11) is supported with the tool body, is movable along the axis of the socket body, and is brought into contact with a front end of the bolt in the nut receiver. The ultrasonic sensor emits and receives ultrasonic waves to detect an axial force acting on the bolt. A sensor spring (45) pushes the ultrasonic sensor to the front end of the bolt.