Thread Rolling is a metal rolling process used extensively in the manufacturing of screws, bolts, and other fasteners. Thread rolling involves forming the threads into the metal of a blank by a pressing and rolling action between two dies. The die surfaces hold the shape and the force of the action forms the threads into the material.
Producing threads by this method has several benefits. Forming will harden the metal through cold working, does not waste material by cutting, and produces a favorable grain structure to strengthen the part.