Abstract
A new processing system comprised of cold multistage forging, form-rolling and magnetic barrel polishing machines has been developed for producing a wristwatch winding-stem. The winding-stem, which has a minute diameter and long complicated shape with various grooves and threads, can be fabricated into its final shape with this processing system in about 1/8 of the time required by conventional turning and thread rolling processes. Cold multistage forging can be accomplished in just two steps. These two steps include the processes of wire shearing, backward extrusion and collar upsetting. Grooves and threads in the winding-stem can be simultaneously formed in only one step using the form-rolling machine with nat tools. The corner of the winding-stem produced with this processing svstem can be distinctly finished. The surface appearance is also smooth without large defects. Mass-production and practical application of a cheap winding-stem may now be realized as a result of this processing system.
