SEMS Screws are screws pre-assembled with free spinning washers. The assembly typically contains one plain washer and one split spring washer. The washers are held in place with the major diameter of the thread being larger than the hole of the washer. This is achieved by inserting the washers before thread rolling.
SEMS screws provide design and manufacturing efficiencies by combining multiple parts, captive washer and screw, into one versatile fastener.
This has many benefits which have revolutionised assembly manufacturing processes, particularly in the Aerospace Avionics sector.
Suitable for many electronic assemblies with smaller space availability.
SEMS can be used anywhere where a screw and washer(s) are required. Application examples below: