In high-stress, dynamic mechanical environments, standard hex nuts are consistently prone to rotational loosening caused by vibration, thermal expansion, and shear stress. ODM Hex Lock Nuts solve this challenge by integrating high-precision prevailing torque mechanisms.
As a leading global exporter, Sinsun Hardware manufacturers high-grade hex lock nuts—including nylon insert lock nuts (compliant with DIN 985/ISO 10511) and all-metal prevailing torque nuts (DIN 980V). These fasteners are engineered to retain preload and maintain clamping force under severe dynamic loads.
Our global presence spans infrastructure projects, automotive assemblies, and renewable energy installations. By controlling the manufacturing workflow from raw material processing to final thermal treatment, we deliver thread-locking components that stand up to the most demanding international safety and engineering standards.
Our structural and mechanical hex lock nuts are manufactured using precise grades of carbon steel and alloy steel, heat-treated in-house to achieve optimal tensile strength and yield ratios. The table below outlines the core mechanical specifications of Sinsun Hardware's custom lock nut solutions.
| Specification Parameter | Nylon Insert Lock Nuts (DIN 985 / ISO 10511) | All-Metal Prevailing Torque Nuts (DIN 980V) | Heavy Hex Flange Lock Nuts (IFI 100/107) | |
|---|---|---|---|---|
| Material Range | Carbon Steel (Class 5, 8, 10); Stainless Steel A2/A4 | Alloy Steel (Class 8, 10, 12); AISI 304/316 | Medium Carbon Steel, Boron Steel, Stainless Steel | Medium Carbon Steel, Boron Steel, Stainless Steel |
| Vibration Resistance | High (suited for standard structural shear loads) | Extreme (suited for high heat & structural impact) | High (combines locking with load distribution) | |
| Working Temp. Limit | -50°C to +120°C (limited by nylon ring polymer) | -60°C to +300°C (governed by metal alloy properties) | -50°C to +250°C (depending on finish and design) | |
| Surface Coatings | Electro-Zinc, Hot Dip Galv, Dacromet, Geomet | Phosphate, Cadmium, Zinc-Nickel, PTFE Coating | Zinc Flake, Electro-Brass, Plain Oiled | |
| Common Applications | Automotive, Machinery, Electronics, Consumer Goods | Heavy Engine Mounts, Railway Bogies, Petrochemical | Solar Trackers, Structural Steel Frames, Pipelines |
Since our founding in 2006, Sinsun Hardware has transformed from a localized production plant in Northern China into a vertically integrated, technology-driven exporter supplying critical hardware globally.
Established a specialized factory focused entirely on high-quality self-tapping screws and core fastener geometry.
Founded our dedicated export department, sending premium fasteners to key global markets.
Added 4 spheroidizing furnaces & in-house wire drawing, guaranteeing raw material control from the source.
Imported German multi-station cold heading machinery to produce complex custom lock nuts and drill tail screws.
Achieved 36,000 tons annual production and shipped 1,100+ export containers to worldwide partners.
Activated our 1,200㎡ ready-stock warehouse program, streamlining regional distributions and reducing lead times.
Commissioned 4 state-of-the-art continuous heat treatment lines, securing absolute hardness consistency (HRC 28-32).
The demand for high-strength hex lock nuts is expanding rapidly. Urban transit networks, green energy farms, and large-scale industrial machinery depend on lock nuts that resist continuous operational stress. Sinsun Hardware coordinates custom manufacturing pipelines to support projects in regions facing harsh climates, where humidity, marine salt spray, and extreme cold threaten connection stability.
In response to modern sustainability demands, our global supply chains are turning toward environmentally friendly surface coatings. Trivalent zinc plating and chrome-free coatings (such as Geomet and Dacromet) have become the default choice for major engineering projects, delivering up to 1,000 hours of salt spray resistance without using hazardous chemicals.
Additionally, structural integrity standards require tight control over tightening torques. Uncontrolled torque can lead to structural damage or yield failures in high-tensile bolts. Our QA lab tests clamping force limits and friction values to guarantee predictable torque values for onsite assembly crews.
Prevailing torque engineering offsets vibration-induced loosening under heavy cyclic loading conditions.
Trivalent zinc and chromium-free finishes protect against corrosion without structural embrittlement.
Tight tolerance controls (within ±0.02mm) deliver consistent friction values during installation.
Sinsun Hardware controls every step of production. We source high-grade steel from Xingtai Steel, process drawing coils in-house, handle precision cold-heading with German machinery, and execute in-house thermal hardening.
We start with premium wire rods from XING TAI Steel, performing internal spheroidizing annealing to refine the microstructure before heading.
Precision Taiwanese tooling and German multi-station cold headers allow us to shape nuts with high dimensional accuracy (±0.02mm).
Our 4 continuous heat treatment lines precisely manage annealing and hardening cycles, ensuring a uniform HRC 28-32 range.
Providing top-tier fasteners requires matching quality manufacturing with efficient, reliable delivery and logistics systems.
To prevent transit damage and storage corrosion, Sinsun Hardware offers customizable packaging options (such as heavy-duty cartons, weather-resistant plastic pails, and steel-strapped pallets). With a smart 12,000 m² warehouse storing up to 18,000 pallets, we keep catalog lines ready to ship, reducing lead times for our global distributors.
Our multi-lingual sales and support offices work closely with clients to supply custom box designs, barcode labeling, and full shipping documentation. This ensures quick customs clearance and direct integration into your warehousing or retail networks.
The non-threaded nylon collar at the exit of the nut has a smaller inside diameter than the bolt's major diameter. When the bolt reaches the collar, it forces its way through the nylon. This compresses the polymer and creates a constant radial force that increases thread friction, preventing loosening from vibrations.
All-metal lock nuts can be reused, but their prevailing torque decreases with each installation as the deflected thread profile gradually conforms to the bolt. For high-vibration applications, we recommend replacing the nut after 3 to 5 installations to ensure reliable locking performance.
Thread galling often occurs when stainless steel threads rub together under high speed and pressure. To prevent this, we recommend using differing grades of stainless steel (e.g., A2 nuts on A4 bolts), applying specialized anti-seize lubricants, or opting for custom nuts coated with wax, PTFE, or zinc flake finishes.
Standard nylon inserts (typically made from Polyamide 6 or 66) perform reliably between -50°C and +120°C. Exceeding 120°C softens the nylon, reducing its locking force. For high-temperature setups (such as exhaust manifolds or furnaces), all-metal prevailing torque nuts are recommended.
High-strength fasteners require high preload tension to function correctly. If the installation torque is too low, the connection can fail from fatigue; if it is too high, it can strip the threads or yield the bolt. Precise torque adjustments, accounting for the friction of the locking mechanism, are essential.
We use modern automated plating systems alongside regular magnetic and X-ray thickness measurements. This keeps our coating thickness uniform (typically 5 to 15 microns), preventing interference with the threads while providing excellent corrosion resistance.
Need custom thread profiles, specialized coatings, or high-volume global shipping? Fill out your details below, and our engineering team will get back to you with custom drawings and pricing.
Contact Our Engineers
