Flange Bolts

Introduction to Flange Bolts

Flange bolts are specialized, high-performance fasteners designed to streamline assembly and improve joint stability. They feature an integrated, washer-like circular flange situated directly beneath the Hexagon Drive or 12-point head. This design inherently eliminates the need for a separate load-distributing washer. By providing an expanded bearing surface, flange bolts effectively distribute the clamping force across a much larger area. This critical feature significantly reduces localized stress on the mating material, preventing yielding and ensuring a robust, long-lasting connection, particularly in dynamic or high-vibration environments.

Materials and Finishes

Built to withstand severe mechanical stresses, flange bolts are manufactured from premium materials including Carbon Steel, Alloy Steel, and Stainless Steel. To meet diverse structural demands, they are available across multiple high-strength grades: 8.8, 10.9, 12.9, A2-70, and A4.

To combat corrosion and extend service life, a wide array of protective finishes is offered:

• Zinc Plated and Hot-Dip Galvanized for standard environmental protection.
• Zinc-Aluminium Flake Coating and Zinc Flake for superior resistance against harsh corrosive agents.
• Black Finishes for specific aesthetic or low-reflectivity requirements.

Technical Specifications and Standards

Flange bolts are precisely engineered to meet rigorous international standards, ensuring reliable performance across critical applications.

• Head Styles and Bearing Surfaces: Featuring an Integrated Flange, the Underhead Features can be specified as Plain for smooth load distribution or Serrated to bite into the mating surface, providing superior resistance to vibration-induced loosening.
• Tensile Strengths: Capable of sustaining tremendous forces with ratings of 800 MPa, 1040 MPa, and up to 1220 MPa.
• Thread Types: Available in comprehensive thread configurations including ISO Metric, UNC, UNF, UN, and BSW.
• Standards: Fully compliant with a broad spectrum of industry benchmarks such as ASTM A320, EN 1665, ASTM A490, ASTM A325, ASTM A193, ASTM F3125, ISO 4162, DIN 6921, and JIS B 1189.

Common Applications and Industries

The unique load-distributing and anti-vibration characteristics of flange bolts make them essential in highly demanding sectors. They are heavily employed in:

• Automotive Industry: Extensively used in engine assemblies, chassis construction, and suspension frameworks where secure, vibration-resistant connections are critical.
• Heavy Industrial Machinery: Providing reliable fastening for equipment subjected to continuous dynamic loads and severe operational stresses.
• Structural Engineering: Utilized in frameworks where the integrated flange prevents surface damage during high-torque installation and ensures consistent clamping force.

Conclusion

Flange bolts represent a highly efficient and reliable fastening solution, combining the strength of a high-tensile bolt with the load distribution of a built-in washer. Their ability to resist loosening under vibration and prevent material yielding makes them a cornerstone component in modern automotive and industrial engineering.