ABSTRACT
The threads are obviously an important element of the threaded fastener. They give this sturdy, industrial product its unique ability to be installed, removed, and reinstalled as many times as we wish. They also affect fastener performance in a major way. Thread type, thread class, thread configuration, the way in which the threads are produced, and the fit between male and female threads can affect not only thread strength-and therefore fastener tensile strengthbut also the resistance of the fastener to such things as self-loosening and fatigue. The amount of preload achieved for a given torque can be influenced by thread configuration and by whether the threads have been cut or rolled. All things considered, it's worthwhile to take a close look at threads.
