Screw and Washer Assemblies (SEMS) are a bolt combination consisting of a single washer or multiple washers permanently attached. However, SEMS is now recognized generally as a common term that applies to washer and screw assemblies. When it comes to pre-assemblies, lock washers are an integral component. At Gear your premier SEMS washer manufacturer, we offer pre-assembled SEMS washers for secure connections.
SEMS Washers :-
The permanently fixed washer of SEMS screw and washer assemblies remains in place because it is installed on a blank bolt prior to thread rolling. The washer remains in place without becoming loose from the bolt because the threads are larger than the initial diameter.

Prior to thread rolling, the washers are installed on the bolt blank. Normally, a washer would potentially slide on the non-threaded area of a bolt. The washers are kept tight with the bolt because of the outside diameter of the threads grows larger than the inside diameter of the washers