Thread rolling, in modern manufacturing, has an extremely high productivity rate, significantly higher than producing threaded parts by machining. Machining is the alternative method for industrial manufacturing of threaded parts. Producing threads by this method has several other benefits over machining. Forming will harden the metal through cold working, does not waste material by cutting, and produces a favorable grain structure to strengthen the part with respect to its function.

The result of moving the material grains into the shape of the thread rather than weakening it by removing material is that the grains become denser at the critical parts of the thread, especially in the root and on the flank below the pitch diameter. This effect improves the quality of the thread form. Additionally, the burnishing action of the steel dies produces an excellent micro-finish. The superior finish improves assembly between external and internal threads and reduces wear between mating components, thereby extending their life. A smooth finish is another advantage that rolls threaded components have over other threaded components.

Thread Inspection

We maintain a large inventory of calibrated thread gauges and inspect threads to both industry and customer standards. Typical industry specifications include AS8879, MIL-S-7742, Handbook H28, and ANSI specifications. Since our focus is on precision threads, we inspect all threads with indicating type variable gauging and maintain a wide range of English standard and metric thread gauges to cover the full spectrum of common and special sizes. Thread ring gauges are used for reference, but indicating gauging is necessary to adequately measure proper thread functionality.

Centerless Grinding for Thread Rolling

Though threads can be rolled on turned, screw machined, or headed parts; a final sizing process is often preferable. The highest quality threads are produced from the highest quality blanks. Centerless grinding of the pre-roll thread diameter (pitch diameter) is one of the most important steps in the process of rolling high precision threads. Centerless grinding permits us to develop the correct pitch diameter prior to roll thread and control the diameter within .0004 inch. (10 microns). Roundness is controlled within .000050 inch (1.25 microns), concentricity is ensured, and the grinding process provides a diameter with an excellent surface finish prior to thread rolling. Typically, customers supply their machined components at a specified oversized diameter and we centerless grind the finished diameter as part of our multi-step process to produce the highest quality rolled threads.

We also have the capability to provide centerless grinding services for threaded and non-threaded components.