Thread Manufacturing

Thread Manufacturing

Thread Manufacturing - It is a fact that more screw threads are produced each year throughout the world than any other machine element. Consequently, several basic procedures have been developed for making these hundreds of millions of screw threads so that they can be produced in several forms, with varying degrees of accuracy.

As in most such cases, the cost of making a screw thread, aside from the cost of the material, varies greatly depending on the accuracy required, the hardness and ductility of the material and, very importantly, the configuration of the workpiece. These are factors over which the designer exercises direct control.

 A screw thread, technically, is a ridge of uniform section in the form of a helix on the external or internal surface of a cylinder or in the form of a conical spiral on the external or internal surface of a cone or frustrum of a cone. Threads on cylindrical surfaces are called straight threads, and those on a cone or frustrum of a cone are called tapered threads.

Tapered threads are used on pipe joints and other applications where liquid tight joints are required. Straight threads, however, are used in a wide variety of applications, the most common being on fastening devices, such as bolts, screws, and nuts, and as integral elements of parts that are to be joined together. To a lesser degree they also are used to transmit motion, as in the lead screw of lathes and other machine tools, and to provide accurate, controlled motion for measuring purposes, as in micrometer calipers.