Carbon Steel Hex Sems Screws Zinc Plated Lock Washer Pre Installed Class 4.8 For Industrial Equipment

Sems screws are fasteners that come with a washer already installed on the screw. You do not need to pick up a separate washer and put it on the screw. This saves time on the assembly line.

The washer sits under the screw head and stays there. It cannot fall off. You just grab the screw and drive it in. The washer is right where you need it.

Metric M3 M4 M5 M6. Lengths from 6mm to 30mm. Custom sizes available.

Electronics assembly. PCB mounting. Control panels. Industrial equipment. Automotive parts. Marine enclosures. HVAC units. General factory assembly.

Saves time. No loose washers to lose. One part to stock instead of two. Faster production line.

Thread gauging on every batch. Hardness testing. Class 4.8 and 6.8 options. Custom orders welcome. Bulk pricing. Direct shipping.

General: Screw Type: Sems Screws, Head Style: Phillips Pan Head / Hex Head / Socket Head Cap, Washer Type: Spring Washer / Flat Washer / Lock Washer

Material: Stainless Steel: 304 Grade, Carbon Steel: Zinc Plated, Strength: Class 4.8 / Class 6.8

Dimensions: Thread Size: M3 M4 M5 M6, Length: 6mm to 30mm

YH Fastener operates an ISO 10012 certified measurement management system. This certification ensures that all our measuring equipment including calipers, micrometers, thread gauges, hardness testers, and optical inspection devices are regularly calibrated and maintained according to international standards.

What this means for you is accurate and traceable measurements on every fastener we produce. Our measurement data is reliable and consistent batch after batch. For customers requiring tight tolerances, our ISO 10012 system provides full confidence in our dimensional inspection reports.

We maintain strict calibration records for every measuring instrument in our facility. Each instrument is calibrated at scheduled intervals by qualified technicians using traceable standards. Any instrument found out of tolerance is immediately removed from service and all affected batches are re-inspected.

This commitment to measurement accuracy is part of our promise to deliver fasteners you can trust.