Automotive Metric Flange Bolts

In the automotive manufacturing, repair, and modification fields, every connection point directly impacts the safety of drivers and passengers. Traditional standard bolts are prone to loosening in the high-frequency vibration environment of a moving vehicle, especially in critical areas such as the engine and chassis. A connection failure in these areas can lead to serious safety accidents.  At the same time, automotive assembly demands extremely high efficiency and component compatibility. Traditional bolts requiring additional washers not only increase inventory management costs but also slow down the assembly line.

Our Automotive Metric Flange Bolts are specifically designed to withstand high-frequency vibrations and extreme operating conditions in vehicles. They are widely used in engine, chassis, suspension, and body systems, providing reliable connection solutions for global automotive manufacturers and the repair market.

Core Technological Advantages

1. Superior Anti-Loosening Performance, Suitable for High-Frequency Vibration Conditions

Continuous high-frequency vibration during vehicle operation is the main cause of bolt loosening. Our flange bolts feature a serrated structure on the bolt head. When tightened, the serrations firmly "grip" the connecting surface, generating significant frictional resistance. This fundamentally prevents the bolt from loosening due to vibration, a level of anti-loosening performance unmatched by ordinary bolts, providing core safety assurance for critical connections in the engine, chassis, and other areas.

We use high-quality carbon steel (such as C1035) and alloy steel (such as 40Cr, 35CrMo) as raw materials, combined with strict tempering heat treatment processes, to produce products with different strength grades, including 8.8, 10.9, and 12.9. The ultra-high strength characteristics give the bolts excellent tensile strength and fatigue resistance, allowing them to easily withstand extreme conditions such as high temperature and pressure in the engine and complex stresses in the chassis. They are resistant to fracture and deformation during long-term use.

A variety of surface treatment processes are available, including natural finish, electro-galvanizing, hot-dip galvanizing, and Dacromet coating. Dacromet treatment offers excellent corrosion resistance, effectively resisting erosion from rainwater and road salt, making it particularly suitable for outdoor automotive environments, extending the bolt's service life and reducing maintenance and replacement costs. 2. Integrated Flange Design for Improved Efficiency and Workpiece Protection

Even Load Distribution Protects Body Material: The flange increases the pressure-bearing area between the bolt and the workpiece, effectively preventing the bolt head from embedding into soft materials commonly used in automobiles, such as aluminum and plastic.  It also ensures even distribution of pre-tightening force, preventing component damage caused by stress concentration and guaranteeing the integrity and service life of automotive parts.

Simplified Assembly and Cost Savings: The flange and bolt head are an integrated structure, eliminating the need for separate flat washers or spring washers as with traditional bolts. This design not only simplifies inventory management (BOM) for businesses and reduces the number of parts, but also significantly improves production efficiency on the assembly line and reduces manual assembly costs.

3. Precise Fit and Excellent Interchangeability

Manufactured strictly in accordance with international and national standards such as ISO 4162, DIN 6921, and GB/T 5787, the thread specifications cover the full range of metric sizes: M6, M8, M10, M12, M14, and M16, with strict control over dimensional accuracy. Perfect interchangeability ensures that the product can be precisely adapted to the assembly needs of different vehicle models, allowing for quick matching and use in both new car manufacturing and after-sales maintenance.

Assisted Positioning in Some Scenarios: In the assembly of components such as car seat frames and instrument panel brackets, the flange can assist in positioning, ensuring precise component installation and guaranteeing the overall assembly accuracy and user experience of the vehicle.

Core Technical Parameters

Typical Application Scenarios

With years of experience serving the automotive industry and a deep understanding of automotive structures, our products have been successfully applied to core automotive systems, becoming a trusted choice for numerous automotive manufacturers and repair companies:

1. Engine and Power System: Used for connecting engine cylinder heads, oil pans, transmission housings, flywheels, and other components. Our products can withstand the high temperatures and pressures during engine operation, providing stable anti-loosening performance and ensuring efficient operation of the power system.

2. Chassis and Suspension System: Used for fixing control arms, shock absorbers, and steering gears. This is one of the areas in automobiles with the highest requirements for anti-loosening performance. Our Automotive Metric Flange Bolts effectively resist continuous vibration and complex forces during driving, ensuring the stability of the chassis structure and improving driving safety and comfort.

3. Body and Interior: Used for connecting key components such as seat frames, seat belt anchor points, and instrument panel brackets. Every bolt directly impacts the safety of the occupants, and our products, with their reliable strength and stability, provide solid safety protection for those inside the vehicle.

4. Wheel System: Suitable for fixing wheel hubs and brake discs in some vehicle models. Under high-speed driving and frequent braking conditions, our products maintain secure connections, preventing wheel safety hazards caused by bolt failures.

Company Strength and Quality Assurance

We are Ningbo Gangtong Zheli Fastener Co., Ltd. Since our establishment in 2001, we have built a mature full-chain system for fastener research and development, production, and sales. Our factory is located in the Zhenhai Chemical Industrial Zone in Ningbo, and our headquarters and foreign trade sales department are located in the Ningbo Jiangdong Eastern Business Center.  Our factory covers an area of 15,000 square meters, with a stable monthly production capacity of 2,000 tons and annual sales exceeding US$15 million. The company is equipped with a professional R&D team, a full-process supply chain management system, and large-scale warehousing facilities. We specialize in the production of various fasteners and can provide integrated MRO (Maintenance, Repair, and Operations) procurement and distribution services for metal fasteners, comprehensively meeting the diverse procurement needs of automotive industry customers. In the automotive industry, there's no room for "almost good enough" quality. We have established a comprehensive quality control system throughout the entire process to ensure that every Automotive Metric Flange Bolts meets stringent standards:  In raw material control, we only select high-quality wire rods that meet the standards, and conduct spectral analysis before warehousing to precisely control the chemical composition and eliminate material defects from the source; in manufacturing processes, we use multi-station cold heading and thread rolling processes to ensure continuous metal flow lines inside the bolt and precise external dimensions; in finished product testing, each batch of products undergoes hardness testing, tensile testing, torque testing, and salt spray corrosion testing (according to surface treatment requirements), and unqualified products are never allowed to enter the market. The company fully implements the ISO 9001 quality management system standard, and some products have passed CE certification, meeting the environmental protection and safety requirements of the international automotive industry.

Our product range is extensive, including Automotive Metric Flange Bolts for automobiles, as well as heavy-duty hexagonal bolts, heavy-duty hexagonal nuts, threaded rods, studs, washers, screws, etc.  Materials include carbon steel, alloy steel, and stainless steel, strictly adhering to international standards such as DIN, ISO, EN, JIS, ASTM/ANSI/ASME/SAE, BS, and AS. Our products are exported to North America, Europe, Australia, Southeast Asia, the Middle East, Latin America, and many other regions, and are widely used in automotive manufacturing, building steel structures, bridges, oil pipelines, mechanical equipment, and many other fields.

Reasons to Choose Us

1. Direct supply from the source factory, outstanding cost-effectiveness: We are a physical manufacturer located in China's fastener industry cluster, possessing advanced production equipment and a complete supply chain, enabling independent production throughout the entire process from raw materials to finished products. Without intermediaries earning a profit margin, we can provide customers with highly competitive ex-factory prices. Standard specifications are readily available in stock, allowing for quick response and delivery.

2. Professional technical support, precise matching of needs: Our engineering team has extensive experience in the automotive fastener industry and is familiar with the assembly requirements of different vehicle models and parts. Whether it's for new vehicle development and matching or after-sales maintenance and replacement, we can provide customers with professional selection advice and technical consulting to ensure that the products precisely match the application scenario. 3. Flexible Customization + Efficient Delivery, Hassle-Free Cooperation: In addition to standard products, we support non-standard customization services. We can tailor products with specific lengths, diameters, strengths, or surface treatments based on customer-provided drawings or requirements. With ample inventory and an efficient logistics system, we guarantee on-time delivery and provide comprehensive after-sales service to fully support our customers' production schedules.