Patent ID: 11725922

Abstract:
A length measuring jig measures the length of a tubular stud bolt with a central hole defined axially therethrough while the tubular stud bolt remains mounted on a target product such as a steam turbine casing. The length measuring jig includes a rod to be inserted into the central hole in the stud bolt, a first jaw provided on a tip end of the rod for abutting against an end face of the one side in longitudinal direction of the stud bolt, a slider on which the rod is slidably supported, a second jaw provided on the slider for abutting against an end face of the other side in longitudinal direction of the stud bolt, and a cap to be fitted in the central hole in the stud bolt and having a slit defined therein for allowing the rod to extend therethrough. The first jaw has an overall length smaller than a diameter of a minimum-diameter portion of the central hole in the stud bolt. The cap has an inner wall surface defining an end of the slit in the cap, and a distance to the inner wall surface from a central axis of the stud bolt is equal to a radius of the minimum-diameter portion of the central hole in a state in which the cap is fitted in the central hole in the stud bolt.