RECALIBRATE
Recalibrate it yourself and every time you use it too.
Here is a cheesy way to do it yourself, any one of you can figure out how to make a better fixture to hold the wrench assembly firmly in place, this is a "Proof of Concept"
1) Lay a 4x4 piece of wood beside your bathroom scale.
2) assemble torque wrench, 6" extension and a crescent wrench together, crescent wrench jaws adjusted to grip the square drive of the extension.
3) Lay the assembled wrenchs so the extension rests across the 4X4 and the tip of the crescent wrench handle presses down on the bathroom scale when you push down on the torque wrench handle. (this will read out in pounds)
4) measure the distance from the centerline of the extension to the tip of the handle that presses down on the scale, in feet. (I measured 7.25" which = .604 feet for mine)
5) set torque wrench to desired value, apply torque to test rig, observing the pounds on the scale when the torque wrench clicks.
6) Multiply the pounds observed from the scale by the distance from the fulcrum to the scale to get the measured torque. ( for example 100 pounds X .60 ft = 60 ft-lbs)
7) re-adjust your wrench until you get the true torque you desire, then go tighten your assembly.
Click stop wrenches are handy, but mine are all way off. I try to use a beam type whenever possible.
This is not an 'official' calibration, so you can't use it on a certified engine or plane, but you could use it to verify or disqualify a wrench.
