- Machine screws with pre-assembled lock washers
- Features a free-spinning internal tooth lock washer beneath the head
- Internal tooth lock washer provides a clean, finished look and prevents snags
- Single part design saves time and hassle
- Excellent solution for bulk projects of production lines
- Zinc plated steel
1/4"-20 Phillips Pan Head SEMS with Internal Tooth Lock Washers are essentially a pre-assembled machine screws with lock washers (similar to a Keps Nut). The lock washer is beneath the head of the screw and is free-spinning. This pre-assembly saves time and hassle on production lines and in any application where a machine screw with lock washer may be necessary, since they do not need to be put together, and there is no need to worry about losing a screw or washer. Internal tooth lock washers are often used over external for their finished edge that hides the locking teeth for a finished look, or snag prevention for close parts. Because of the integrated lock washer, SEMS screws are often referred to as lock screws, or locking screws.