SEMS screws are used in applications where loosening is a concern. They come pre-assembled with a free spinning lock washer, which is permanently held in place by the major diameter of a screw’s thread. This eliminates the need for hand-assembling washers onto the screw, saving time, resources, and the potential for lost or dropped washers in the production line.
The Internal Tooth Lockwasher SEMS are used with smaller heads or in applications where it is necessary to hide the washer teeth for appearance or to prevent snags.
In addition to in-house dimensional inspections, each lot is performance-tested based on ASME specifications for ductility, drive, torsional strength, and hydrogen embrittlement.