Phillips trimmer screw with integrated washer, P-3

A SEMS trimmer bolt with integrated washer is a type of hex socket screw in which a spring washer and a flat washer are pre-assembled, preventing the washers from detaching.

This helps avoid assembly errors such as forgetting to install washers and improves assembly efficiency.

It is also referred to as a SEMS screw or a combined screw (組込ねじ).

Depending on the type and washer combination, there are variations such as P-2 (spring washer only) and P-3 (spring washer + flat washer).

The P-3 type comes pre-assembled with a spring washer (SW per JIS) and a flat washer (JIS old-style “machined round washer”).

※ Applicable standards: JIS B 1187, GB9074.17

※ Note: The integrated washers are standardized international components matched with the screw body.