https://www.mrmetric.com/?leadsource=MC1127 SEMS screws combine two separate components into one pre-assembled, cost-effective fastener. These handy devices combine the screw and the washer into a single part, eliminating the need to match the right items up and slip the washer into place by hand. It also simplifies your inventory by giving you one part to track and purchase instead of two.
SEMs typically come with some form of lockwasher to prevent slippage once the screw is firmly secured. Two popular choices include internal-tooth and external-tooth lockwashers. Double SEMs contain two washers instead of just one. In addition to a lockwasher, a double SEM also has a flat washer that sits on top of the locking washer. Of course, sometimes all these options can get a little confusing. Which SEM is right for your needs?
Well regarded as experts in metric, contact us 1-866-501-9504 and we’ll be glad to discuss it with you and help you with your purchase. Mr. Metric is the leading metric fastener specialist in North America.