What does 63+-7 mean? 56 - 70 lbs? Tightening my sway bar
^^^ That. I have several torque wrenches, all are + / - 3 to 5 lbs /fpsThey have a tendency to move back and forth any ways so your good, I think they give you a range because torque wrenches ( depending on brand) are not spot on they usually have a +/- 2 on the better makes
Good information, old dog learned new trick.I will throw this in just as an extra piece of wisdom. A dial indicator torque wrench is better than a click torque wrench if you are truly anal in what you are tightening. Using a dial torque wrench as you are tightening the bolt you can watch the dial and as it tightens the reading should climb at a fairly even rate. If you are tightening the bolt and the reading slows or stops for a short period of time the bolt is bad and needs to be replaced because it has stretched beyond the limits set for that bolt. A click type torque wrench you will not notice how the bolt reacts to torque and could loosen after use causing problems.
To clarify, subtract 20% of the max torque rating from the bottom end of use.It does. Never use the bottom 20% of the range.During my time in the service I was also told by the calibration guys that a percentage of the bottom range was not considered accurate either. That was in the late 80's, so I'm not sure it that holds true today.
I'm not trying to spell check you, just adding to the discussion.In addition, the +/- rating of the torque wrench should also be subtracted from the top and lower torque ratings.
Example: continuing with the 0-100 ft lbs wrench above, assume the torque wrench is calibrated to +/- 8%. 8% of 20 = 1.6; 8% of 100 = 8 Therefore, the usable range of a 0-100 ft lbs torque wrench calibrated to 8% is 21.6 to 92 ft lbs.