They are used as cushion springs or spacers between parts on shafts or to take up expected amounts of variation in assembled parts. The washers are available in two series: the A 7X-9-3W thin wall and MB3401 screw size. The A 7X-9-3W, available in only stainless steel, comes in 0.265 to 0.856-in. IDs, and the MB3401 comes in 0.075 to 0.531-in. IDs. Both are designed to fit screw sizes ranging from 0 to 1/2.

Stock Drive Products, 2101 Jericho Turnpike, Box 5416, New Hyde Park, NY 11042, (516) 328-3300, www.sdp-si.com