When using click wrenches, the torque applied to the bolt is higher than the value set for the click. This happens because the operator does not stop immediately after the click.
The smaller is the “breaking” angle of the click wrench, the higher is the probability to apply torque higher than the preset click torque.
For this reason, when testing/calibrating a click wrench, a “First Peak detection” algorithm must be use in the torque analyzer system, to detect the click point instead of the maximum torque.
Using the first peak, results are normally more repetitive and give the measure of the precision of the click mechanism of the wrench regardless the operator skills.
It must be considered anyway that the real torque applied to the bolt when using click wrenches is the Maximum Torque.
Therefore, to evaluate the real torque applied to the bolt, including the effect of the operator, the torque analyzer system must be set to measure the Maximum Torque.
An operator training about the correct use of a click wrench, together with the use of proper torque analyzer system to control and calibrate the click-point, are fundamental requirements to assure a correct tightening process on a production line.