Inside diameter measuring tool

摘要

An inside diameter measuring tool includes: a main body (10); an axially moving spindle (15) having a male screw (14) to be screwed to the main body (10); a plurality of contact pieces (22) provided on the main body (10), the measuring pieces (22) moving in a direction substantially orthogonal to the axial direction of the spindle (15); and a conical member (23) interposed between the contact pieces (22) and the spindle (15), the conical member advancing and retracting the contact pieces (22) in the direction substantially orthogonal to the axial direction of the spindle (15). The lead of the male screw (14) of the spindle (15) is 1.0 mm or more and the cone angle of the conical member (23) is less than 53 degrees. Preferably, the lead of the male screw (14) is 2.0 mm and the cone angle of the conical member (23) is approximately 28 degrees.