A SEMS screw (also known as a pre-assembled screw or combi screw) is a screw or bolt that comes pre-fitted with one or more permanently attached, free-spinning washers.

Why Use SEMS Screws?

Speeds Up Assembly:

Factory workers or automated machinery don’t have to spend extra time manually picking up and placing tiny washers onto screws before driving them.

Prevents Omitted or Lost Washers:

Eliminates human error (forgetting to install a lock washer) and prevents dropped washers from falling into sensitive electronics, machinery gears, or engines.

Simpler Inventory:

Reduces part counts on your Bill of Materials (BOM). Instead of ordering, tracking, and stocking screws and washers separately, you manage just one component.