Flanged Hex Head Bolt

Do you want to buy discount and quality Flanged Hex Head Bolt? Our dear customers all around the world, you are welcome to buy that from our factory in China. Flanged hex head bolts are high-strength fasteners that combine a hexagonal head with an integrated flange.  Their unique design integrates the flange and bolt head into a single unit, eliminating the need for separate washers and ensuring even load distribution, preventing loosening, and significantly improving the sealing and stability of the connection.

They are widely used in applications requiring high reliability, vibration resistance, and installation efficiency, such as automotive engines, transmissions, industrial pumps and valves, compressors, agricultural machinery, steel structures, and new energy equipment. The enlarged bearing surface of the flange effectively reduces the risk of crushing the connected parts, making them particularly suitable for connecting soft materials (such as aluminum alloys and cast iron) or thin-plate structures.

This series of Flanged Hex Head Bolt is manufactured in strict accordance with international and national standards such as ISO 4762, DIN 6921, and GB/T 5789, ensuring dimensional accuracy, thread compatibility, and stable and reliable mechanical properties. They are the ideal choice for "efficient, reliable, and washer-free" connections in modern industrial assembly.

Core Performance and Technological Advantages

Based on our over 10 years of experience in fastener R&D and mass production, combined with materials science, mechanical testing, and actual customer application scenarios, our flanged hex head bolts possess the following core advantages in design and manufacturing:

1. Integrated Flange Design for Enhanced Connection Reliability

- Flange Diameter: Typically 1.5–2 times the thread diameter (e.g., M10 bolt flange diameter is approximately 18–22mm), significantly increasing the bearing area.

- Uniform Load Distribution: Reduces localized stress concentration, preventing deformation or crushing of the connected parts.

- Built-in Locking Function: The flange edge can be designed with a serrated structure (Prevailing Torque Type) to provide self-locking and anti-loosening performance, suitable for high-vibration environments.

2. Multiple Materials and Strength Grades to Suit Different Working Conditions

- Carbon Steel Series:

- Grade 8.8: General purpose, tensile strength ≥ 800MPa

- Grade 10.9: High strength, tensile strength ≥ 1040MPa, used in engines and heavy machinery

- Grade 12.9: Ultra-high strength, tensile strength ≥ 1220MPa, suitable for high pre-tension connections

- Alloy Steel/Chromium Molybdenum Steel: Suitable for high-temperature and high-pressure environments (e.g., exhaust systems, pressure vessels)

- Stainless Steel Series:

- A2-70 (304): Resistant to general corrosion

- A4-80 (316): Resistant to chloride ion corrosion, suitable for marine and chemical environments

3. Precision Manufacturing Process Ensures Consistency and Reliability

- Cold Heading One-Step Forming: The head and flange are cold-headed as a single piece, resulting in continuous metal flow lines, improving tensile and shear strength.

- Rolled Threads: High-precision rolling process, smooth thread surface, accuracy up to 6g grade, ensuring perfect fit with nuts.

- Heat Treatment Control: Quenching and tempering treatment ensures a balance of strength and toughness, preventing brittle fracture, conforming to GB/T 3098.1 standard.

4. Advanced Surface Treatment for Extended Service Life

- Carbon Steel Models Available with:

- Cold Galvanizing: Environmentally friendly, salt spray test resistance ≥ 72 hours

- Dacromet: Chromium-free, environmentally friendly coating with corrosion resistance exceeding 500 hours, and no risk of hydrogen embrittlement.

- Hot-dip galvanizing: Suitable for long-term outdoor exposure environments.

- Stainless steel models: Naturally passivated, no electroplating required, environmentally friendly and long-lasting rust prevention.

5. Resistant to extreme environments and adaptable to complex working conditions

- Operating temperature range: -60°C to +400°C (depending on material and surface treatment)

- Excellent vibration and shock resistance, suitable for high-speed rotating equipment and earthquake-prone areas

- Passed vibration tests, salt spray tests, and preload retention tests to ensure long-term stability

Typical Application Scenarios

Our flanged hex head bolts have been successfully applied in various industries and key projects:

Automotive manufacturing: Engine cylinder heads, transmission housings, suspension system connections, reducing washer usage and improving assembly efficiency

Industrial equipment: Pump bodies, compressors, reducer flange connections, preventing leaks and loosening

Agricultural machinery: Tractor and harvester transmission systems, resistant to high vibration and impact

New energy equipment: Wind power pitch control systems, photovoltaic bracket connections, strong weather resistance

Steel structure engineering: Node plates, support connections, replacing traditional "bolt + washer" combinations, simplifying installation

Why choose our flanged hex head bolt? Authoritative Certification, Traceable Quality

- Certified with quality and environmental management systems including ISO 9001, IATF 16949, and ISO 14001.

- Products comply with multiple international standards such as ISO, DIN, GB, JIS, and ANSI, and are exported to Europe, America, Japan, South Korea, and Southeast Asia.

- Each batch is provided with a Mill Certificate, test report, and certificate of conformity, enabling full lifecycle traceability.

Owned Production Lines, Full-Process Quality Control

- Self-built cold heading, heat treatment, thread rolling, and surface treatment workshops, mastering core processes.

- Equipped with professional equipment such as spectrometers, tensile testing machines, salt spray testing chambers, metallographic microscopes, and hardness testers.

- Achieves full-process quality monitoring from raw material warehousing to finished product delivery.

Professional Technical Support and Customer Service

- Provides CAD drawings, torque recommendation tables, installation specifications, and anti-loosening solutions.

- Supports sample delivery, non-standard customization, OEM labeling, and bulk supply.

- Professional technical team provides 24/7 online support to solve selection, installation, and usage problems.

FAQ

Q1: What is the difference between flanged hex head bolt and ordinary hex head bolts?

A: Flanged bolts have an integrated flange, which can replace washers, providing a larger bearing surface and anti-loosening function, resulting in more efficient installation.

Q2: Can serrated flanges or special lengths be customized?

A: We support customization of serrated flanges, full threads, fine threads, and special lengths. Please provide drawings or technical requirements.

Q3: What applications are suitable for 12.9 grade bolts?

A: Suitable for high pre-tension connections, such as engines, pressure vessels, and heavy machinery, requiring strict control of tightening torque.

Q4: How to prevent flanged bolts from loosening during vibration?

A: It is recommended to use serrated flange type, combined with lock nuts or thread locking adhesive to improve anti-loosening performance.

Q5: What are the minimum order quantity and delivery time?

A: The minimum order quantity for standard products is 500 pieces. Samples are shipped in 3-5 days, and bulk orders in 7-15 days. Expedited production is available.