TORQUE INFORMATION
- In this section, learn more about Torque and how it is measured, how to specify the Torque value of fasteners, and how to correctly tighten Bolted Joints. There is also a handy guide to Torque Units and conversion factors, a Torque Glossary and a Torqueleader Torque conversion programme to help you convert between the different types of torque units.
- The information on this page is available as downloads above
WHAT IS TORQUE?
- Torque is the application of a Force acting at a radial Distance and tending to cause rotation
- Torque is used to create tension
HOW?
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Referring to the diagram below, it can be seen that as the nut and bolt are tightened the two plates are clamped together. The thread converts the applied torque into tension in the bolt shank. The amount of tension created in the bolt is critical
WHY?
- The tension in the bolt creates a clamping force between the two parts. If the clamping force is too low, the fasteners can work loose due to vibration or movement between the component parts. If a clamping force is too high, the fastener may permanently stretch and no longer apply the required clamping force. In severe cases the fastener may fail in assembly or during use when under load. Clamping force is generally referred to as the preload
HOW IS TORQUE CALCULATED?
- Torque is the result of multiplying the value of Force applied by the Distance from the point of application
- Comparing the two examples below (A and B) it will be noted that the same resultant torque can be achieved with a lower Force if the Distance from the nut/bolt is increased
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It should also be realised that some Torque Wrenches are length dependent which means that the actual torque applied to the fastener varies if the hand position on the wrench is varied - even with the wrench preset. This occurs if the pivot point of the wrench mechanism is not coincidental with the point of application of torque
- The information is available as downloads