The International Standards Organisation (ISO) recommend the use of the Newton metre (N.m) to denote the ‘base' torque unit.
Q. Why is Torque important?
Fasteners tightening is done in order to stop objects from moving--to fix them. The following are the major objectives of fastener tightening:
1. For fixing and joining objects
2. For transmitting driving force and braking force
3. For sealing drain bolts, gas, and liquid
The fixing force is referred to as axial tension or tightening force and the objective of screw tightening is to apply an appropriate amount of axial tension.
Although axial tension is really what needs to be controlled and measured, it is very difficult to do so, therefore torque is used as a substitute characteristic for administering and controlling tightening operations.
Q. What are the methods of inspecting the Tightening Torque?
Estimate how much torque was applied in the screw tightening, and carry out an inspection of the tightening operation with the following methods.