High-performance custom standard and non-standard mechanical components designed to withstand structural fatigue and extreme loading conditions.
Years Fastener Manufacturing Experience
Tons Annual Production Capacity
Traceable Quality Inspections
Comprehensive Customization Standards
VLC is a leading bolts and screws manufacturer in China. With about 20 years of expertise in fasteners production and technology, we have annual output of 10,000 tons bolts, studs, screws etc, especially hex bolts, structural bolts and studs. Our factory leader started the first personal owned business in 2006, with a mission of becoming customers’ first choice for fasteners manufacturers in China.
As modern industries push limits with higher pressures, heavier loads, and harsher environments, standard fasteners often fail to provide the structural integrity required. High-performance tension bolts serve as critical structural links that maintain secure clamping force over long-term operations. Our specialized focus on custom OEM tension bolts allows engineers worldwide to specify detailed parameters, including thread configurations, metallurgy, dimensional tolerances, and surface treatments to prevent joint slippage, fatigue failures, and structural relaxation.
The technical principles governing structural tension joints and how custom manufacturing satisfies demanding applications.
Tension bolts work by generating a precise preload clamping force when tightened. The elastic elongation of the bolt body exerts a compressive force on the joined components. Maintaining this force is essential to prevent joint fatigue under cyclic dynamic loads, demanding precise calculation of torque-tension relationships.
Standard thread cutting interrupts the grain structure of the alloy steel, leading to stress concentration points. VLC utilizes specialized cold rolling threads after heat treatment to generate compressive residual stresses at the thread roots, significantly improving the bolt's resistance to fatigue under tension load cycles.
Selecting the optimal metallurgical grade is vital. We work extensively with alloy steels (40Cr, 35CrMo, 42CrMo) and high-performance stainless steel grades. Heat treatment is strictly controlled to ensure optimal yield-to-tensile ratios, achieving property classes 8.8, 10.9, 12.9, or custom requirements.
VLC integrates high-capacity manufacturing processes to produce reliable, high-yield tension fasteners with tight dimensional tolerances.
High-precision turning for custom dimensions, non-standard shanks, complex shoulders, and custom head configurations designed to optimize clamping load distribution.
Multiaxis CNC milling and machining centers capable of creating critical non-standard components, ensuring exact matching configurations for specialized assemblies.
Optimized for high-speed, high-efficiency production of smaller custom inserts, sleeves, and specialized washers that form part of multi-component tension joints.
Our automatic lathes production line allows VLC to optimize cycle times for medium and high-volume orders. This enables us to offer competitive pricing on custom fasteners while maintaining strict concentricity and surface finish guidelines, preventing structural micro-fissures during cold heading and high-speed turning.
VLC manufactures bespoke tension bolts to meet global engineering standards and tough operational conditions.
| Material Group | Common Material Grades | Tensile Strength (MPa) | Surface Treatment Options | Typical Applications |
|---|---|---|---|---|
| Alloy Steel | 40Cr, 35CrMo, 42CrMo, SCM435, SCM440 | 800 to 1220 (Class 8.8, 10.9, 12.9) | Black Oxide, Zinc Flake (Geomet), Hot Dip Galvanizing | Wind Turbine Tower Joints, Heavy Engines, Bridges |
| Stainless Steel | A2-70, A4-80, Duplex 2205, Super Duplex 2507 | 700 to 1000 | Passivation, Electro-polishing, PVD | Marine Equipment, Offshore Oil & Gas, Chemical Reactors |
| Super Alloys | Inconel 718, Monel K-500, Titanium Grade 5 | 900 to 1400 | Anodizing, Dry Film Lubricant | Aerospace, Subsea Flanges, High-Temp Exhausts |
| Carbon Steel | C35, C45, 10B21 | 500 to 800 (Class 5.8, 6.8) | Electro-Zinc Plating, Yellow Zinc, Plain | Structural Frames, DIY Hardware, Light Industrial |
How our integrated operations and strategic location support global procurement requirements.
VLC leverages China's industrial manufacturing ecosystem to secure premium steel wire rod feedstock, high-efficiency heat treatment facilities, and advanced surface finishing services. This geographical integration allows us to:
By controlling the production cycle from raw material testing to final cold forging, threading, and shipping, we ensure compliance with international quality parameters.
Procuring fasteners globally requires adhering to strict regulatory frameworks. VLC provides technical and compliance support for target markets in Europe, the Americas, and the Asia-Pacific region:
VLC fasteners are engineered for demanding industrial environments requiring reliable safety performance.
Used in wind turbine tower segments, foundation anchor bolts, and rotor blade joints. These fasteners resist constant cyclic wind loads, preventing fatigue-induced joint loosening.
Applied in industrial gearboxes, internal combustion engines, and hydraulic presses. High-preload fasteners maintain compression under thermal expansion and vibration.
Integrated into steel structure bridges, rail track systems, and high-rise structural skeletons, providing structural stability that conforms to international safety standards.
Innovative developments shaping high-strength fastening technologies.
Modern industries are adopting tension bolts with integrated ultrasonic or wireless sensors. These "smart bolts" allow maintenance technicians to monitor preload tension in real-time, reducing inspection times and preventing catastrophic failures in wind farms and high-pressure chemical installations.
Environmental mandates have led to a shift away from traditional cadmium plating and hexavalent chromium coatings. VLC offers dry-film lubricants and thin-layer zinc flake coatings. These provide high corrosion resistance and steady friction coefficients without compromising environmental standards.
Answers to common engineering and procurement queries regarding custom tension fastener specifications.
We use specialized torque-tension testing equipment to measure the friction coefficients of both threads and underhead bearing surfaces. This ensures that when target torque is applied during field installation, the calculated axial preload tension is achieved within engineered limits.
High-strength bolts (Class 10.9 and above) are vulnerable to hydrogen embrittlement, particularly after acid pickling or electroplating. VLC manages this risk by using mechanical cleaning or controlled acid pickling, followed by immediate baking in de-embrittlement ovens to drive off residual hydrogen.
Yes. Our in-house engineering team works with standard formats (STEP, IGES, DWG) to program our multi-axis CNC machines and automated manufacturing lines, facilitating precise transitions from digital design to physical prototype and production.
Our capacity ensures we can meet large bulk demands for infrastructure projects, maintaining structural integrity across production runs and helping supply chains remain consistent.
VLC offers specialized structural bolts, anchor systems, and customized CNC fittings for industrial and commercial projects.
VLC Part
