Thread Rolling Using Fixed and Movable Flat Dies

Thread Rolling Using Fixed and Movable Flat Dies

Thread Rolling Using Fixed and Movable Flat Dies - One process of thread rolling, shown schematically, begins with a plain cylindrical blank with a diameter that is sized partway between the major and minor diameters of the finished thread.

The blank material must be sufficiently plastic to flow and to withstand the stress of cold working without disintegrating. The thread is formed by rotating and squeezing the blank between hardened steel dies whose working surfacesare the reverse of the thread form to be produced.

Action of Die Forming Thread

The threads of the die penetrate the surface of the blank as it rolls between them. The displaced material forms the roots of the thread and, at the same time, is forced radially outward to form the crests. Thread rolling dies may be either flat or cylindrical.