Originally Posted by
kycycler
As a former aircraft mechanic for major airline I can state unequivocally that the only way to guarantee the accuracy of any torque wrench is to have it tested against a standard at a calibration lab.
There is no more
accurate way to calibrate torque wrenches than properly conducted deadweight tests.
One of the reasons that regulated industries such as aircraft send their wrenches out for testing has more to do with law than precision. These days government regulators frown on self certification, so by sending the wrenches to a third party they not only get accurate calibration, but third party verification that it was done.