Patent ID: 7918031

Claim:
A thread ring gauge comprising: a body including inner and outer peripheries spaced in a radial direction, with the inner periphery having threading, with the body including a split extending from the outer periphery through the inner periphery in the radial direction, separating the body into first and second sections respectively having first and second end faces facing each other, with the split formed between the first and second end faces, with the first end face including a first hole extending in a width direction perpendicular to the radial direction, with the first hole interposed between and spaced from the inner and outer peripheries in the radial direction, with the second end face including a second hole extending in the width direction and coaxial with the first hole, with at least one of the first and second holes extending to the outer periphery, with the first end face including a first groove extending away from the second end face in the width direction, with the first groove extending from the outer periphery towards but spaced from the inner periphery in the radial direction, with the first groove having a bottom wall facing the second end face, with the second end face including a second groove extending away from the first end face in the width direction, with the second groove extending from the outer periphery towards but spaced from the inner periphery in the radial direction, with the second groove having a bottom wall facing the first end face; a first adjusting member received in the first and second holes, with the first adjusting member being movable to adjust a width of the slit between the first and second end faces in the width direction; a first gauge block received in the first and second grooves and abutting the bottom walls of the first and second grooves, with the bottom walls of the first and second grooves being arcuate, and with the first gauge block being cylindrical and having circular cross sections; and a second gauge block having circular cross sections with a diameter smaller than that of the circular cross sections of the first gauge block, with the first gauge block being replaced with the second gauge block when the threading of the inner periphery becomes worn, and with the second gauge block abutting the bottom walls of the first and second grooves.