Thread rolling uses hardened steel cylindrical dies to shape ductile metals. The dies, imprinted with the thread profile, penetrate the work metal at ultra-high pressures to displace and mold it into a mirror image thread. This process differs from traditional cutting and grinding methods because no metal is lost or cut away.
Thread rolling improves tensile strength by 10% - 30% or more and fatigue strength by between 50-75% due to the hardening of the material during the rolling process. In addition to withstanding greater tensile, shear and fatigue loadings, the work hardening of the thread surface results in greater resistance to wear, corrosion and galling.