Rolling

Thread rolling is a cold deformation: here too, as in all permanent deformations, the material is stressed beyond the elasticity limit, so it becomes plastic and remains deformed. From a technical point of view, the rolled threads show a remarkable accuracy of the profile. By virtue of the pressure-polished surface, the corrosion resistance is significantly improved.

The resistance of the starting material improves in the areas deformed by rolling with an increase in the compressive strength against the threads obtained with the traditional chip removal. A pressure preload system is obtained at the base of the thread, which improves resistance to alternating stresses, increasing the duration of the product over time. The trend of the metal fibers, which has no cuts or interruptions, but follows the profile of the thread itself, is a guarantee of safety against breakage.

Advantages of rolling: improvement of the mechanical characteristics

Cold working of the surface increases the tensile strength of the processed material, and static tension tests have frequently recorded increases over normal values. Furthermore, since in the rolling of the threads the fibers of the material are not cut as in the conventional methods, but reshaped in continuous lines that follow the contours of the thread, the resistance to breaking by torsion is considerably higher than the average.

Finally, the resistance to fatigue, given the greater adherence ensured by the smoothness of the rolled threads, also increases compared to normal values.
By rolling, it is possible to obtain, in addition to triangular threads, trapezoidal, special threads and knurls