Hex Sems Machine Screws Custom Metric Stainless Steel Sems Screw Manufacturer

Short Description:

YH Fastener makes high quality sems screws in stainless steel and carbon steel, full metric sizes in stock, OEM custom welcome, ideal for vibration-resistant electronics and sheet metal assembly.

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Product Details

For assembly lines that use separate screws and washers, missing parts, uneven locking force and low efficiency are common headaches. Our sems screws solve this by pre-assembling the screw and washer into one single piece — no more manual washer placement, cutting assembly labor and reducing loose fastening issues. We have been making sems fasteners for nearly 30 years, with mature process and stable quality for all kinds of industrial fastening needs.

Integrated Structure & Anti-Loosening Performance

Each sems screw presses the matching washer onto the shank before thread rolling, so the washer stays permanently fixed and never falls off during packing, shipping or installation.

Compared with manually matched loose washers, this integrated design delivers more consistent clamping force and better vibration resistance, especially suitable for high-speed automatic assembly lines. We offer both single-washer and double sems options to match different load bearing and sealing requirements.

Material & Surface Finish Options

We source raw materials from top domestic mills like Baosteel and Taigang, with stable composition and reliable mechanical properties:

304 stainless steel: Natural passivated finish, basic corrosion resistance for indoor and general outdoor use, the first choice for electronics and telecom devices
Carbon steel C1022A / 10B21: Cost-effective for indoor scenarios, available with eco trivalent zinc plating, black oxide and dacromet. Salt spray performance ranges from 48h to 500h based on finish
316 stainless steel: For coastal and mildly corrosive environments, with better chloride corrosion resistance

All material grades comply with international standards, with full batch traceability from raw material to finished products.

Size & Head Type Coverage

We cover full metric sizes from M1.6 to M12, fitting both miniature precision devices and heavy industrial assemblies. Regular sizes M3, M4, M5, M6 are kept in bulk stock for fast dispatch.

Stocked head styles include hex socket head, Phillips pan head and hex washer head. Custom profiles like truss head, flat countersunk head and terminal sems screws for electrical connection can all be made to order.

In-House Quality Control Process

Every production batch goes through strict checks before shipment. We run all finished parts through automatic optical sorting machines for 100% dimensional inspection, covering thread diameter, head thickness and washer outer diameter. We also sample-test torque value, salt spray resistance and washer retention force to eliminate defective goods.

Main Application Scenarios

These sems machine screws are widely used in electronics assembly, server racks, telecom cabinets, sheet metal fabrication, electrical terminals, automotive interiors and furniture hardware. They work best for automatic production lines that pursue high efficiency and stable fastening quality.

About YH Fastener

YH Fastener is a professional sems screws manufacturer based in Dongguan, Guangdong, with nearly 30 years of production experience. We operate two production bases totaling 20,000 square meters, equipped with over 200 sets of automatic cold heading, thread rolling and assembly equipment, with daily output exceeding 1 million pieces.

We control the full production chain in house, from raw material incoming to surface treatment and final inspection, so we can guarantee stable lead time and consistent quality. Our factory holds ISO9001, IATF16949 and ISO14001 certifications, and products are exported to more than 40 countries across Europe, North America and Southeast Asia. We support full OEM/ODM custom services from sample development to mass production.

Inquiry Guide

If you are looking for a reliable sems screw supplier, send us your requirements including size, material, head type, order quantity and any special specifications. Our sales team will reply with a detailed quotation and lead time within 2 working hours. Free stock samples are available for quality evaluation, and small-batch trial orders are accepted. Feel free to contact us for technical consultation or custom solution needs.