Thread rolling- a neglected art

Thread rolling is a generally accepted alternative to cutting for the production of small threaded piece parts such as BA screws and self-tappers. Yet the wider uses of thread rolling have been neglected by production engineers over the years. In this article, Walter H Froehlich describes how the modern two-roll thread rolling machine can produce practically any thread form, including serrations and knurls, in a wide range of sizes on such items as valve stems, lead and ball screws, worms and taps.