In screw thread terminology, the crest refers to the top or outermost edge of the thread profile. It is the highest point of the thread’s cross-sectional shape, where the thread’s diameter is at its maximum.
The crest plays a crucial role in the function and fit of threaded components. For external threads, such as those on bolts, the crest is the part that makes contact with the internal threads of a nut. For internal threads, like those in a nut, the crest is the surface that engages with the external thread of a bolt. Properly formed crests ensure a good fit and reliable mechanical connection between the threaded parts.
The accuracy of the crest is important for maintaining the strength and functionality of the threaded assembly. If the crest is damaged or not within the specified tolerances, it can lead to issues such as poor thread engagement, reduced load-carrying capacity, or even thread failure. Therefore, the crest must be manufactured to precise dimensions as specified by thread standards to ensure proper performance and interchangeability of threaded components.