A sems screw is a cross-recessed machine screw with a free spinning washer. Pre-assembly of machine screw and washer provides cost savings to the end user. Offered in assembly with different washer types like flat for better force distribution and larger bearing surface to compensate for oversized holes and with lock washers designed to make into a locking screw with washer providing locking action. Available and ready-to-ship in a variety of sizes and finishes. Browse our selection of sems screws for your building projects and industrial applications.