Do you think you know the difference between bolt tensioning and torquing, and which system is best?
Both have the same objective; to create a clamping force that holds parts together. Tensioning is a better system, but not always practical, or necessary. We can help you decide whether one method is better for your application
Tell Me About Tensioning:
Using high pressure fluid, typically oil, these systems transfer force that stretches bolts while turning the nut.
The objective of tensioning is to stretch the bolt, or stud, to a predetermined load, by using force to elongate the shank. This is accomplished using a pulling or pushing force which is created by a hydraulic cylinder. The nut can then be seated manually using a wrench. Very little turning force is required. It is necessary to have some extra thread above the nut, which is used to attach the pulling cylinder, which is removed after completion.
MAIN ATTRIBUTES:
• Stability and ease of control
• Highly accurate
• Generally more expensive than other systems
• Most often used on large bolts
Why You’d Bother With Torquing
The objective is to stretch the bolt or stud to a predetermined load. The stretching is accomplished by turning the nut, which pulls the shank due to the ramp angle of the threads.
The nut is rotating against the surface of the component which is being clamped. As the clamp load increases, the friction between the nut and the surface of the component increases to a predetermined amount.
MAIN ATTRIBUTES
• Less accurate than hydraulic tensioning
• Less expensive to purchase
• More versatile
• Usually used on smaller fasteners
• Simple to use
When deciding on the type of tool to use for attaining the desired clamp load, it is important to consider the engineering specifications.
If tensioning is specified, it must be the selected method. If torque is specified, it may be possible to use tensioning, if accessible. Many torque specifications allow a wider accuracy, making tensioning unnecessary.
If you need a hand sorting out the best method for your application, we can help. We’ve worked with wind farms and other power generation facilities, mines, petrochemical businesses and more. Contact us to arrange a demo today.