Cold molding process is the use of plastic deformation processing of metal parts principle of a process approach.
    Generalized cold metal forming process have been two thousand years of history, for example, ancient Chinese gold and silver jewelry is the use of metal processing Roll forming machine and plastic deformation theory, hand-forged for a cold forming process. However, the use of modern means, using automatic cold heading machine machining metal parts, or 30-40 years of the twentieth century, developed rapidly during World War II. The United States in World War II, the use of bolts and other fasteners are produced by cold forming process. At that time, more developed industries in Japan, also uses cutting, only a small screw in the process of cold forming process used in production. China's cold molding process is the first Five-Year Plan period from the introduction of the former Soviet Union, the small screw technology similar to Japan, while the multi-stage forming process is the beginning of the sixties.

        Second, the typical single-station cold forming process

        Forming a single station and double-click two points, but at present most of the single-station double-click the shape, double-click is the most common cold upsetting upsetting, as it includes a wide range of products, all kinds of construction, the nails of various shapes first, as long as the material length 5.5dm below can be formed.

        Double-click the shape, the first challenge for the pre-heading, with a conical cavity of the rough top punch into the die, so rough on the center, to prevent vertical bending, and precision punch make the second impact preparation, pre-upsetting the early completion of the punch, the Forming machine blank into a conical free end. With a conical punch in the beginning of upsetting the beginning, all the impact entirely concentrate on the top die nailed. Die in the rough pole also upsetting to screw blank size requirements, fine after upsetting the head size requirements also completed. Order processing after the product varieties under different processing. Such as the hexagon head bolts, the need for cutting-edge technology, cut out the hexagon and then carry out the order of thread rolling and heat treatment or surface treatment. If machines screw, the screw in Figure 2, there are two processes: one is the first form of upsetting speak out, and then slotting another thread rolling; the other process is the use of heading a cross slot and slotted, you can twist wire the.