| Miniature ball screws use internal ball return and reportedly provide high efficiency and repeatability, precise positioning, and smooth, reliable motion. Diameters start at 4 mm, with a 1-mm lead. Six and 8-mm diameters are also available. Manufactured as both rolled and ground units, the ball screws come in a range of precision classes. Nylon wipers protect against contamination, and ends can be machined to customer specifications. Thomson Industries Inc., 2 Channel Dr., Port Washington, NY 11050, (800) 554-8466, www.thomsonindustries.com | 