Explore our flagship industrial fastener inventory. Direct factory shipping, ISO-certified quality manufacturing, and custom surface engineering capabilities.
In industrial assembly environments subject to continuous vibration and thermal cycling, conventional nuts run a high risk of back-off. Serrated washer flange nuts (complying with standard specifications like DIN 6923, EN 1661, and ASME B18.16.4) represent one of the most effective mechanical locking solutions available. By combining an integrated washer profile with specialized one-way directional locking teeth, these fasteners eliminate the need for separate lock washers, reducing assembly time and component costs.
When tightened, the integrated serrations on the flange face bite directly into the mating material, creating a high-friction mechanical interlock. The angle of the serrations is specifically engineered to resist counter-clockwise rotational forces. As a result, the break-away torque required to loosen a serrated washer nut is typically 1.2 to 1.5 times greater than the initial tightening torque. This ensures the integrity of electrical, automotive, structural, and mechanical connections over years of operation.
We manufacture serrated washer lock nuts to tight tolerances using high-precision Taiwanese tooling and advanced multi-station cold forming machines.
| Parameter Name | Standard Reference | Range / Specification Details | Target Applications |
|---|---|---|---|
| Nominal Sizes | DIN 6923 / ASME B18.16.4 | M3 to M20 (Metric); #4 to 3/4" (Imperial) | General machinery, solar mounting racks |
| Material Base | ASTM A510 / JIS G3507 | C1022A Carbon Steel, Stainless Steel (SUS304 / SUS316), Alloy Steels | Automotive assemblies, offshore platforms |
| Mechanical Strength Class | ISO 898-2 / SAE J995 | Class 8, Class 10, Grade G | Heavy duty structures, structural framing |
| Corrosion Protection | ASTM B117 / ISO 9227 | Electro-zinc plating, Geomet, Dacromet (1000+ hours salt spray test) | Outdoor infrastructure, photovoltaic fields |
| Dimensional Tolerances | ISO 4759-1 | Precision Grade A (±0.02mm on critical dimensions) | Automated robotic assembly feeders |
| Surface Polish | ISO 4287 | Ra ≤ 0.4µm (prevents micro-gaps and uneven load dispersion) | Precision automotive & aerospace housings |
With operations rooted in Tianjin, Northern China's industrial fastener capital, Sinsun Hardware integrates raw wire processing, stamping, heating, and packaging under one roof.
Our supply chain begins directly at Xingtai Steel Group, the gold standard for high-performance structural steel. In-house spheroidizing annealing and wire drawing ensure superior microstructure consistency, preventing cracking during the rapid cold-heading processes.
Sinsun operates over 200 German-imported multi-station cold heading machines and Taiwan-engineered tooling components. We execute forming speeds exceeding 1,200 pieces per minute while holding dimensions to a strict ±0.02mm limit.
Four custom continuous carburizing and tempering heat treatment lines process up to 20 tons of fasteners daily. Control of quenching temperatures and atmospheric carbon levels achieves a stable core hardness of HRC 28-32.
Tracking Sinsun Hardware's trajectory from a regional supplier to an international structural fastening leader.
Established state-of-the-art cold forging facility in Northern China, focusing initially on self-tapping screw fabrication and high-strength industrial nuts.
Secured ISO 9001 certifications and launched dedicated export lines servicing distributors across Europe, South America, and the Middle East.
Imported German multi-station forming machinery and Taiwanese tooling units to scale product offerings to over 20,000 active SKU lines.
Constructed a 12,000 sqm automated warehousing facility, added 4 continuous atmospheric gas heat treatment lines, and reached an annual capacity of 36,000 tons.
Reliability is non-negotiable. Sinsun products undergo a rigorous 12-step inspection process to verify absolute compliance with ASTM, ISO, DIN, and custom corporate criteria.
Our quality department contains analytical testing equipment, including spectrum alloy analyzers to check raw wire chemistry, profile projectors for thread geometry checking, micro-hardness testers, digital torque testers, and continuous salt-spray chambers. Testing covers:
Every shipment is backed by a complete documentation package, including Material Test Reports (MTRs), Plating Thickness verification Certificates, Heat Treatment logs, and compliance documentation for RoHS and REACH regulations.
Navigating complex international trade barriers requires strong supply chain integration, regulatory reporting, and reliable logistics planning.
Sinsun provides verified carbon footprint documentation. This supports our European buyers in complying with the Carbon Border Adjustment Mechanism (CBAM) reporting requirements.
By optimizing our global distribution routes and maintaining structural cost efficiencies, we help importers navigate and mitigate anti-dumping tariffs in their local jurisdictions.
Our 12,000 sqm warehouse holds over 18,000 pallets. An ERP-managed picking system allows us to support just-in-time logistics and load up to 50 containers daily.
Read how Sinsun Hardware partners with global engineering firms to resolve connection failures and reduce assembly weight.
Challenge: A tier-1 automotive components provider experienced bolt loosening in engine housing assemblies under high vibration.
Solution: We supplied customized Class 10 carbon steel serrated flange lock nuts with specialized thread locking profiles and low friction coefficients.
Result: Loosening issues were resolved. The assembly withstood 2,000 hours of continuous vibration testing with zero joint failures, allowing for a 15% reduction in overall fastener weight.
Challenge: Saltwater spray caused corrosion in fasteners on solar panels installed on offshore structures within six months.
Solution: Sinsun supplied M12 Duplex Stainless Steel (Grade 2205) serrated nuts finished with a passivation layer and a PTFE coating.
Result: Rust issues were resolved. Joint integrity was maintained with zero failures, and the installation's maintenance cycle was extended by five years.
From initial requirement analysis to mass production and shipping support, we maintain strict step-by-step control.
We review your operating conditions, temperature fluctuations, chemical exposure, vibration levels, and target mechanical loads.
Our engineering team creates 3D models and runs simulations to optimize the serration angle, flange contact area, and tooth spacing.
We supply pre-production samples for physical torque, tension, hardness, and salt spray testing in your assembly environment.
Upon prototype approval, mass production starts on cold heading lines, with key dimensions verified at scheduled intervals.
Fasteners undergo heat treatment and coating. Samples from each batch are tested, and MTRs are compiled.
Products are packed in custom OEM/ODM packaging and loaded directly at our 12,000 sqm facility for shipment.
Technical information on ordering, custom designs, materials, and international delivery.
While Sinsun is optimized for high-volume container shipments, we accommodate smaller MOQs for new projects and prototype testing. Please share your drawings and volume requirements with our sales team.
Yes. Custom fabrication from technical drawings is one of our primary capabilities. We manufacture to international standards, including ISO, DIN, ANSI, ASME, and JIS, using materials like carbon steel, stainless steel, and alloys.
Quality control is built into each stage. We monitor raw materials from Xingtai Steel, check parts during production, and conduct final laboratory tests on hardness, torque, tension, and corrosion resistance. Complete MTR documents are supplied with every order.
Lead times depend on the specification, finish, and quantities required. Standard fastener products are typically delivered in 4 to 6 weeks. We provide a firm delivery timeline with every quote.
Yes. We supply samples for testing, dimensional checks, and application verification before beginning mass production.
For high-tensile fasteners (Class 8, Class 10, and above), we run a post-electroplating baking cycle. This process removes hydrogen from the material core, preventing brittle failures in critical stress applications.
Direct factory logistics, optimized transport planning, and global container delivery options across all major industrial markets.
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