torque wrench calibration

[95burgundyesi]

So I left my torque wrench on 100 overnight. Is there a way to test if it is within spec still?

 

[NN4S]

The cheapest way is to test it with a beam style torque wrench with the same range; you could have it calibrated, but it's going to cost a bit to get that done. You should have a beam wrench for each range anyway, and they are dead easy to tell if the zero is correct or not. A note of caution: ALWAYS buy quality tools, the amount you'll spend in the end on multiple cheapies will pay for the well-made ones in the long run and you'll get a lot more pleasure out of using them.

To verify it with the beam wrench, use a 12 point socket the correct size to fit the drive (I'm guessing 1/2" from your 100 lb. setting) and connect the two with it. Use some soft jaws in your bench vise (or wrap the handle evenly with pieces from an old leather belt) to hold the clicker-type wrench horizontal (drive side up) by the grip after setting it to the range that you want to verify. Align the wrenches so that they are on top of each other and then pull steadily on the beam wrench while noting the scale reading. When the clicker breaks torque (click!), the reading on the beam is your correct setting. The better the resolution of the beam scale, the more accurate your assessment will be. You can make a chart for later comparison of the wrench by checking the settings across the range and recording your results; by running a comparison once or twice a year, you'll be able to know if there's any degradation of performance so that you can have the wrench professionally repaired/calibrated or replace it.

 

[95burgundyesi]

Thanks for that tip, but I just returned it to the store and said it was not within spec and I got a brand new one from the warrenty.

 

[Defiant]

For future reference, leaving a clicker set to a value for a week won't matter to it. You aren't getting an accurate enough torque on it to be worried about in the first place.
Always use a nice, cheap, rock-simple beam torque wrench when you can. It shows you if things are slipping or seizing on the way to a given value.