The reference datum for a screw thread is the pitch diameter cylinder. Although a defined method within the United states for pitch diameter measurement exists, it does not follow worldwide procedures, and the complexity and uncertainties associated with this measurement often go unappreciated. Some of the problems associated with using a coordinate measuring machine (CMM) for measurements on both external and internal threads are discussed.
Citation: Chapter in: Structural Integrity of Fasteners, STP 1236, P.M. Toor, Editor
Publisher Info: American Society for Testing and Materials, Philadelphia, PA
Pub Type: Books
CMMs, coordinate measuring machines, measurements, pitch diameter, screw threads, thread measurement, threaded fasteners, threads