How to easily identify a ball screw assembly

06 September 2016

Thomson Industries Incvisit website


Thomson Industries Inc has released an educational video that demonstrates simple techniques to help design engineers identify ball screws assemblies.

Randy Hamper, Senior Design Engineer at Thomson, says: “Customers needing to replace worn ball screw assemblies sometimes aren’t sure exactly what kind of assembly they are using. We created this video to demonstrate some simple techniques to help determine whether they have a metric - or inch-based assembly and to understand how ball screw and lead dimensions are used to characterise ball screws. Following these simple steps will shorten the time it takes to replace worn assemblies and run their processes with new precision.”

Ball screw assemblies differ according to whether they are metric or inch scale, by the ball circle diameter and by the number of leads on the screw. In this two-minute video, Hamper shows how to tell instantly whether the assembly is metric - or inch-based by looking at the ball return path. He demonstrates how to measure ball screw circle diameter with callipers, how to wrap a string around the threads to aid in determining whether it is a 1, 2, or 4-start screw and how all of these measurements play out in ball screw assembly naming conventions.

To view the video, please visit or via YouTube at For more information about Thomson ball screw assemblies please visit

© Copyright 2006-14 Damte Ltd.