Formed thread

Illustration of Formed thread

Threads formed by deformation and thus obtaining special properties

Threads formed by material removal [1] have an interrupted internal microstructure.
 
Threads formed with a form tap or roll tap undergo a plastic deformation process [2] where the inner microstructure is reshaped and largely follows the thread profile. In addition to eliminating any problems with chip transportation, formed thread has higher tensile strength than cut threads.
Threads
Spiral shaped outer or inner grooves are usually used for fitting
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