When it comes to bolted joints, the importance of accurate torque and preload values cannot be overstated. However, with the introduction of friction into the equation, things can get a bit more complicated. In this article, we will explore the relationship between torque, preload, and friction, and how it can impact the performance of bolted joints.
Firstly, let's define some terms. Torque is the rotational force applied to the bolt head or nut to tighten it, while preload is the tension force that the bolt exerts on the joint when it is tightened. The purpose of achieving a desired preload is to ensure that the joint remains secure and resistant to external forces. Friction, on the other hand, refers to the resistance that is present when two surfaces come into contact with each other.
Now, let's look at how friction affects torque and preload. When applying torque to a bolt, some of the force is used to overcome friction between the bolt and the surface it is in contact with. This means that not all of the torque applied is being used to tighten the bolt, resulting in a lower preload. Therefore, it is important to take into account the amount of friction present in the joint when calculating the required torque to achieve the desired preload.
One way to reduce the impact of friction on preload is to use lubricants. Applying a lubricant to the thread and the contact surfaces can reduce the amount of friction present, allowing for a higher preload to be achieved with the same amount of torque. However, it is important to use a suitable lubricant that does not negatively affect the performance of the joint.
Another factor that can impact the relationship between torque, preload, and friction is the surface finish of the contact surfaces. A rough surface finish can increase the amount of friction present, resulting in a lower preload for the same amount of torque. Therefore, it is important to ensure that the contact surfaces are clean and smooth to reduce the impact of friction.
In addition to these factors, the material properties of the bolts and joint components can also impact the relationship between torque, preload, and friction. For example, a bolt with a higher coefficient of friction will require more torque to achieve the same preload as a bolt with a lower coefficient of friction. Therefore, it is important to consider the material properties of the components when designing and selecting bolts for a specific application.
In conclusion, the relationship between torque, preload, and friction is a complex one that requires careful consideration in order to achieve optimal joint performance. By taking into account factors such as lubrication, surface finish, and material properties, it is possible to achieve a higher preload for the same amount of torque, resulting in a more secure and reliable joint. As the largest manufacturer and supplier of split set products in China, Tanrimine Metal Support Co., Ltd (TRM) takes great pride in providing high-quality friction bolt and plate products that are designed to meet the unique needs of each application. With a full range of accessories and components, TRM ensures that its customers can achieve the desired torque and preload values, while minimizing the impact of friction on joint performance.