Explore our foundational selection of high-precision screws, heavy-duty structural flange bolts, and specialized copper hardware components manufactured under rigorous ISO standards.
A deep look into the structural capabilities, design philosophy, and advanced engineering systems that define modern fastener manufacturing.
Handan Yongnian District Dongshuo Fastener Manufacturing Co., Ltd. was established in 2015. Located in the heart of China’s fastener manufacturing cluster, Hebei Province, our enterprise specializes in the high-capacity production and engineering optimization of industrial fasteners, focusing on structural bolts, specialized screws, nuts, and heavy-duty steel washers.
Over nearly a decade of rigorous process development, we have built a manufacturing infrastructure designed to supply structural engineers, heavy manufacturing clients, and global procurement firms with high-integrity joint components. We pair metallurgical expertise with computerized quality verification, offering customized OEM services alongside strict conformance to DIN, ISO, ASTM, and GB specifications.
Custom CAD/CAM engineering
Metallurgy & stress analysis
High-speed cold heading
The clustering effect of the Yongnian district creates structural economic and technical advantages that directly benefit international industrial buyers.
Our close proximity to Hebei's premium steel manufacturing mills (such as Hansteel and HBIS Group) allows us to source high-grade carbon steel rod coils (Q195, Q235, 35K, 45#, 40Cr, SCM435) with minimal internal transit times and zero degradation from humidity. This integration ensures predictable raw material pricing and constant batch stability.
Dongshuo operates advanced multi-station cold-forging machinery, progressive punching presses, and high-speed rotary thread rollers. Automation ensures strict adherence to geometric tolerances (Class A or B for washers and bolts), lowering the frequency of dimension-driven assembly failures on heavy construction sites.
The Handan fastener cluster provides comprehensive, eco-compliant surface treatment options. From heavy hot-dip galvanizing (exceeding 85μm thickness for marine environments) to precise yellow zinc plating, black oxide passivation, and high-performance zinc flake coatings (Dacromet/Geomet) to prevent hydrogen embrittlement.
A technical overview of the flat, spring, and specialty washer standards critical to securing joints under heavy preloads and cyclic dynamic fatigue.
Steel washers are not mere spacer rings; they are highly engineered components designed to distribute the clamping force of threaded fasteners over a larger surface area. Under the formula for tightening torque:
T = K * D * P
(where T is torque, K is the torque coefficient, D is nominal diameter, and P is clamp force), the uniformity of the washer surface establishes the consistency of the coefficient K.
Without a flat steel washer (such as DIN 125 or ISO 7089), mechanical variations in the structural steel around the bolt hole will lead to localized embedding, causing massive tension loss over time. Conversely, helical spring washers (DIN 127) provide constant axial tension during vibration cycles, preventing rotation-based loosening.
| Standard | Washer Type | Hardness Range | Primary Applications |
|---|---|---|---|
| DIN 125 / ISO 7089 | Flat Plain Washer | 140 HV - 300 HV | General manufacturing, structural engineering, load distribution |
| DIN 127 | Helical Spring Washer | 350 - 430 HV | Anti-loosening, high-vibration applications, automotive engines |
| DIN 9021 / ISO 7093 | Fender/Wide Flat Washer | 140 HV - 200 HV | Thin metal cladding, wood construction, composite materials |
| DIN 6916 / EN 14399-6 | HV Structural Washer | 300 - 370 HV | High-strength structural steel joints, bridge assembly |
| DIN 7980 | Heavy-Duty Spring Washer | 360 - 440 HV | Paired with high-tensile cylinder head bolts & socket screws |
A visual documentation of our production output, advanced packing methodologies, and industrial fastener variety.
Combining heavy hex bolts, spring lock washers, and flat washers in factory-matched configurations to speed up field installation.
Our heavy-duty steel washers, high-tensile bolts, and locking fasteners are engineered for structural integrity across demanding sectors.
High-strength structural connections in skyscrapers, bridges, and high-rise frameworks rely on hot-dip galvanized EN 14399-6 (DIN 6916) washers to safely distribute tension. The surface hardness of these washers is engineered to withstand high torque from impact wrenches without mechanical yield.
Key Standard: DIN 6916 / Class 10.9 AssembliesIn engines, transmission housings, and suspension linkages subject to cyclic mechanical stress, spring lock washers (DIN 127) and integrated flange assemblies ensure that bolts do not back out. Black oxide coatings provide clean lubrication profiles for accurate robotic assembly torque.
Key Standard: DIN 127 / DIN 7980 / custom OEMWind turbine tower structures and solar tracker frameworks require fastening components with decades of outdoor corrosion resistance. We supply specialized washers featuring hot-dip galvanization and Dacromet finishes designed to pass 1000-hour salt spray tests without red rust.
Key Standard: Astm F436 / DIN 9021 Zinc FlakeOperational principles that ensure consistent material quality, pricing stability, and logistics execution.
We offer direct factory pricing, which is fully negotiable based on contract volume, packaging preferences, and long-term procurement schedules.
To assure technical fit, samples are available for performance evaluation. Freight can be coordinated on delivery or via advance payment structures.
All raw steel coils and surface treatment agents comply with international environmental requirements, including RoHS and REACH criteria.
Whether managing full container loads (FCL) or smaller LCL consolidation batches, our logistics staff adapts to your supply chain rhythm.
Send us your exact CAD/CAM drawings, metallurgy profile, and marking requirements. We open custom molds and supply initial articles for physical confirmation.
We maintain continuous communication pathways. Email our export division or initiate a live chat to discuss your technical parameters.
We take pride in providing timely, reliable and useful services for global fastener sourcing.
Detailed engineering and commercial answers to simplify your procurement process for steel washers and industrial fasteners.
Explore our heavy-strength industrial bolting items, drywall fasteners, and self-drilling screws engineered for heavy-torque applications.
Our engineering department is ready to assist you in designing and supplying optimal washer profiles, custom stamping, and heavy industrial fasteners. Reach out to our representatives with your project BOM, blueprint designs, or target technical criteria for a prompt quotation.
When you are keen on any of our items following you view our product list, please feel free to make contact with us for inquiries. You'll be able to send us emails and get in touch with us for consultation and we shall respond to you as soon as we are able to.
Dongshuo