Inspection method of taper threads and apparatus for making the same

摘要

A method for the inspection of male or female tapered threads located at the extremities of metal pipes. The pitch diameter of the threads in a measuring plane located substantially in the middle of a zone of perfect threads is inspected using a plane diameter measuring device while the pitch diameter of the threads is conventionally defined by the specification API 5B in the plane of the last perfect male thread. The pitch diameter of the threads measured is compared with an estimated value calculated from the nominal value of the pitch diameter in the plane P0, from the distance between P0 and P1, and a plot value for the taper, itself a function of the distribution of the tapers formed.