BOLT FASTENING TOOL WITH AXIAL FORCE MEASURING DEVICE

PROBLEM TO BE SOLVED: To provide a fastening tool which is capable of safely and surely fastening a bolt by prescribed axial force without winding lead wire on the fastening tool. SOLUTION: This fastening tool is provided with a socket 2 for fastening in which an insertion part of the head of a bolt 20 in the lower part, an ultrasonic sensor 4 and a coil spring 5 in an internal sensor storage part 3 and a slip ring 6 at the upper outer periphery are provided and a casing 1 in which the upper part of the socket 2 for fastening is inserted into the lower part and a driving motor 9 revolving the socket 2 for fastening, a battery 14 driving this driving motor 9, a signal processor 10 inputting and processing the output signal of the ultrasonic sensor 4 via the slip ring 6 and a contact piece 7, a bolt axial force setting device 12 and a controller 11 controlling the driving motor 9 are provided at the inside.