M30 Hex Bolt

As a professional factory from China, Gangtong Zheli is not only an experienced M30 Hex Bolt manufacturer and reliable supplier but also capable of providing customized solutions based on customers' actual working conditions. M30 hex bolts refer to high-strength fasteners with a nominal diameter of 30mm and a hexagonal head. They are widely used in critical structural components requiring extremely high connection strength, fatigue resistance, and long-term stability, such as bridge engineering, wind power generation, heavy machinery, petrochemicals, steel structures, rail transit, and large equipment installation.

As a core product among large-diameter fasteners, M30 hex bolts not only possess excellent tensile, shear, and preload retention capabilities, but also, due to their standardized design, high assembly efficiency, and reusability, have become the preferred connection solution in modern heavy industrial assembly systems.

Core Performance and Technological Advantages

Based on our 20+ years of experience in the research and development, mass production, and on-site technical service of large-diameter high-strength bolts, our M30 hexagonal bolts possess the following core advantages in terms of materials, processes, precision, and reliability:

1. High-strength alloy materials to ensure connection safety under extreme working conditions

- Material selection:

- 35#, 45# high-quality carbon steel: suitable for 8.8 grade general-purpose connections

- 40Cr, 35CrMoA, 42CrMoA alloy steel: used for 10.9 grade and above high-strength bolts, possessing excellent hardenability and fatigue resistance

- Stainless steel A2-70, A4-80: suitable for corrosive environments, such as offshore platforms and chemical equipment

- Mechanical properties:

- 8.8 grade: tensile strength ≥ 800MPa

- 10.9 grade: tensile strength ≥ 1040MPa

- 12.9 grade: tensile strength ≥ 1220MPa

- All products undergo comprehensive testing including tensile, impact, hardness, and metallographic structure analysis.

2. Precision manufacturing process to ensure dimensional consistency and assembly reliability

- Cold heading: one-piece head forming, continuous metal flow lines, improving tensile strength

- High-precision thread rolling: thread accuracy reaches 6g grade, ensuring smooth mating with nuts and preventing seizing

- Hexagonal head across-flats dimension tolerance controlled within ±0.2mm, compatible with standard wrenches and power tools

- Full thread/half thread options: flexibly meeting different connection length requirements

3. Multiple surface treatments to adapt to different environmental corrosion challenges

- Environmentally friendly electroplating (color zinc, blue-white zinc): salt spray test ≥ 96 hours, suitable for general industrial environments

- Dacromet coating: chromium-free and environmentally friendly, salt spray resistance ≥ 500 hours, no hydrogen embrittlement risk, suitable for coastal and high-humidity areas

- Hot-dip galvanizing: thick coating, long anti-corrosion life of more than 10 years, suitable for long-term outdoor exposed structures Natural/Polished Stainless Steel: Meets high hygiene standards for food, pharmaceutical, and cleanroom applications.

4. Anti-loosening and Pre-tensioning Design for Enhanced Long-Term Connection Stability

- Flange Head Design: Integrated flange distributes pressure stress and prevents loosening.

- Optional Nylon Locking Ring: Provides additional anti-loosening function, suitable for high-vibration equipment.

- Torque-Tension Control Design: Used with a dedicated torque wrench for precise pre-tensioning, avoiding overtightening or loosening.

- Full Thread Version: Facilitates adjustment of pre-tensioning force, suitable for connections requiring multiple disassemblies.

5. Full-Process Quality Control to Ensure Batch Consistency

- Raw material spectral analysis and mechanical testing

- Online production process inspection (dimensions, hardness, thread gauge)

- 100% finished product visual inspection + batch sampling destructive testing

- Material certificate, test report, certificate of conformity, and traceability code provided for each batch

Typical Application Scenarios

Our M30 hex bolts have been successfully applied in several national key projects and high-end manufacturing fields:

Bridge Steel Structures: Used for main beam connections, 10.9 grade hot-dip galvanized bolts, corrosion-resistant and fatigue-resistant.

Wind Power Turbine Towers: Tower flange connections, 12.9 grade high-strength bolts, capable of withstanding cyclic loads.

Heavy Machinery Assembly: Key articulation points of excavators and cranes, ensuring no loosening under high loads.

Petrochemical Equipment: Pressure vessels, pipeline flange connections, A4-80 stainless steel version resistant to chloride ion corrosion.

Rail Transit: Bogie and car body connections, verified through vibration testing and fatigue life testing.

Why choose our M30 hex bolts? Authoritative Certification, Quality Endorsement

- Certified with international standards such as ISO 9001, IATF 16949, ISO 17025, CE, RoHS, and REACH.

- Products comply with multiple national standards including GB, ISO, DIN, ANSI, and JIS, and are exported to over 30 countries worldwide.

- Third-party testing reports from SGS, BV, TÜV, etc., are available.

Self-Owned Intelligent Manufacturing Base, Controllable Process

- Self-built full-process production lines for cold heading, heat treatment, thread rolling, surface treatment, and testing laboratories.

- Equipped with spectrometers, universal material testing machines, salt spray chambers, metallographic microscopes, and torque testers.

- Achieves full traceability management from raw materials to finished products.

Professional Technical Support and Customization Services

- Provides selection guides, torque parameter tables, installation specifications, and CAD drawings.

- Supports non-standard customization (special length, thread, head, strength grade).

- Offers OEM labeling, JIT just-in-time delivery, bulk supply, and on-site technical support.

- Technical team provides 24-hour response to address issues such as installation, loosening, corrosion, and fracture.

Faq

Q1: What are the strength grades of M30 hexagonal bolts?

A: Common grades are 8.8, 10.9, and 12.9, which can be selected according to load requirements.

Q2: Can it be used for long-term outdoor use?

A: Yes, it is recommended to choose the hot-dip galvanized or Dacromet coated version for longer corrosion resistance.

Q3: How to control the installation torque?

A: It is recommended to use a torque wrench or hydraulic tensioner, and refer to the GB/T 16823.3 standard for setting the pre-tightening force.

Q4: Do you support non-standard customization?

A: Yes, parameters such as length, thread, head, strength, and surface treatment can be customized.

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

A: Standard products have a minimum order quantity of 50 pieces, samples are shipped within 7 days, and bulk orders take 20-35 days, with expedited options available.