Precautions During Assembly of High-Strength Bolts

2025-11-10 09:40:28

1. Control of Preload:
   Applying the correct preload is essential to ensure the functionality of high-strength bolts. Proper preload reduces load concentration and increases friction, thus enhancing the stability of the connection. Therefore, engineering personnel must set the appropriate preload value according to design specifications or manufacturer recommendations.

2. Treatment of Friction Surfaces:
   If the friction surfaces at the connection are not properly prepared, the fastening effect will be compromised. It is recommended to clean, degrease, and remove rust from these surfaces before assembly to ensure effective friction performance.

3. Replacement of Bolts:
   Bolts showing signs of thread deformation, corrosion, or other damage must be replaced promptly to avoid compromising the structural integrity. Removed bolts should not be reused in structures requiring similar or higher load-bearing capacity.

4. Selection of Tools:
   Tools used for tightening high-strength bolts must be accurate and comply with the required torque standards. Torque wrenches or other calibrated tightening tools should be used to ensure correct preload. Over-tightening or under-tightening may negatively affect the bolt’s service life and the quality of the connection.

Common Issues with High-Strength Bolts and Their Solutions

1. Bolt Fracture:
   This may be caused by excessive tightening, uneven load distribution, or external impact. During installation, tightening force should be properly controlled and sudden load changes should be avoided.

2. Loosening:
   Long-term vibration or unexpected load variations may cause bolts to loosen. Appropriate countermeasures should be considered in the design phase, such as using lock washers or thread locking agents to improve fastening reliability.

3. Corrosion:
   Corrosion is common for bolts exposed to outdoor or harsh environments. Bolts with good corrosion resistance should be selected, and protective coatings should be inspected and maintained regularly. Replacement is recommended when necessary.

4. Thread Wear:
   Repeated disassembly or improper operation can lead to thread wear, which affects fastening performance and reduces structural stability. Assembly procedures should be strictly followed, and regular inspection of fasteners should be carried out.

About ASM FASTENER

ASM FASTENER is a professional manufacturer specializing in high-strength stud bolts, threaded rods, and corresponding nut assemblies for applications in petrochemical, marine engineering, heavy equipment, and offshore projects.
With over 14 years of experience, ASM FASTENER focuses on producing a wide range of materials including ASTM SA193 B7, B7M, B8/B8M (CL1/CL2), B16, A320 L7/L7M, and other high-performance grades required for high temperature, high pressure, and corrosive environments.
We support custom specifications, third-party inspection, material traceability, and full certification documentation. Our products are widely used in FPSOs, refineries, power plants, and large vessel construction, earning strong trust from global customers.