What is thread pitch, and how is it measured and expressed?
For fractional size fasteners, thread pitch is the number of threads in one inch of threaded length, expressed as threads per inch (TPI). Example: 1/2-13 (1/2″ diameter, 13 threads per inch) For metric fasteners, the pitch is determined by measuring the distance between the crest of one thread to the crest of the adjacent thread, with the distance expressed in millimeters.
