SEMS screws are a type of fastener that combine a screw and a washer into one pre-assembled unit. The name "SEMS" stands for "screw and washer assemblies" and originated from the word pre-asSEMbled bolts. Nowadays SEMs screw is used as a more generic term for bolts that come with pre-assembled washers. All SEMs screws come assembled with a flat washer and spring washer, these washers are installed onto the bolts prior to the thread rolling which prevents them from falling off during assembly or handling. SEMs screws are exceptionally popular in large scale manufacturing and projects where efficiency is key. The flat washer distributes the load, increasing clamping force and the spring washer prevents the screws or bolts from ever coming loose due to any vibration.
SEMs screws are available in both Phillip's No2 drive and Torx drive dependant on your preference. All SEMs screws are a metric coarse thread.
SEMS Screw Assemblies
- Panhead bolt in either PH2 or TX drive
- 1 Pre-assembled flat washer
- 1 Pre-assembled spring Washer
- Bright zinc plated
- Mild steel 4.6 grade
- Further product specific information such as diameters, thread pitches and head dimensions can be found on each product page