How to prevent the loss of pre-tightening force of high strength bolts?

Author: admin / 2023-11-03

To prevent the loss of pre-tightening force of high strength bolt, the following methods can be adopted:

Proper Preload: When installing bolts, make sure you apply the appropriate preload. Preload refers to the tensile force exerted on the bolt. It should be large enough to ensure the stability of the bolted connection, but not too large to cause excessive stress on the bolt. Select the appropriate pretightening force based on the bolt material and specification, as well as the requirements of the connector.

Use appropriate tightening methods: Choosing an appropriate tightening method ensures that the bolt’s preload is adequately maintained. Common fastening methods include manual fastening, torque control and angle control. Manual tightening requires experience and skill, torque control can be achieved with a torque wrench, and angle control requires the use of an angle wrench. Choose the appropriate fastening method according to the specific situation and operate it as required.

Use proper lubricant: When installing bolts, using proper lubricant can reduce friction and help maintain bolt pretension. Lubricant reduces friction between threads, making it easier for the bolt to rotate and achieve the predetermined preload. Choose a suitable lubricant and apply as directed.

Regular inspection and re-tensioning: High-strength bolts may loosen during use, resulting in loss of pre-tightening force. Therefore, regularly check the tightness of the connections and re-pretighten the bolts if necessary. Depending on the situation, develop an inspection and maintenance schedule to ensure bolts are always properly pretensioned.

Use locking devices: For connections with special requirements, you can consider using locking devices to increase the stability and durability of the connection. Common locking devices include nut washers, bolt fixing compounds and spring washers. Select the appropriate locking device according to specific needs and install it as required.

Through proper pre-tightening force, tightening methods, lubricants, regular inspection and re-pre-tightening, and the use of locking devices, the loss of pre-tightening force of high-strength bolts can be effectively prevented and the stability and durability of the connection can be improved. In actual applications, choose the appropriate method according to the specific situation and follow the relevant installation and maintenance instructions.

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