Set the paper aside in a safe space until you need it. Because 24 inches (61 cm) is a common length for most torque wrenches, it will serve as the measurement for further steps.
Be careful not to overtighten the vice and damage the square drive on the torque wrench. Make sure only the square drive itself is caught in the clamp, so the wrench can move under the weight you apply.
If you’re working with metric units, start by converting the weight to Newtons. To do this, multiply the number of kilograms by 9. 807. In this example 9. 07 kg x 9. 807 = 88. 94949 Newtons. Then, multiply the number of Newtons by the length in meters: 88. 94949 Newtons x 0. 6096 meters = 54. 2 Newton meters. To convert foot-pounds to Newton meters, multiply by 1. 35582. For this example, 40 foot-pounds is equal to 54. 2 Newton meters. Be sure to use the correct distance and weight figures. If your wrench is a different size or you’re using different weights, your figures will be different.
Do not securely tie the weight to the wrench. Instead, simply hang it. Be sure nothing is in the way of or supporting the weight as it hangs.
Repeat this process until the torque wrench clicks using the known weight. Be sure to lift the weight off the wrench and lower it again to test for clicking each time.
Keep repeating this process until you stop hearing the click. Be sure to lift the weight off and set it down again each time. Do not slide it up the handle.
Start by moving the weight an inch or so at a time. It’s okay to move up and down the handle of the wrench more than once as you look for the point in which it starts to click.
The part of the handle where it begins or stops clicking is called the transition point.
Be careful not to confuse this number with the figure you recorded in step 2. You may want to test finding the transition point more than once to be sure you have the correct number.
The equation is the same as before: measurement length times weight, divided by 12. If you’re using metric units, convert the weight to Newtons (kg x 9. 807), then multiply the number of Newtons by the length in meters: 9. 07 kg x 9. 807 = 88. 95 Newtons. 88. 95 Newtons x 0. 6604 meters = 58. 74 Newton meters.
Multiplying your intended torque by the difference will give you the correct setting for your specific torque wrench. This solution can keep you working, but the wrench will still need to be calibrated.
The strain on the internal spring can cause the calibration to drift if not left on zero.
Banging a torque wrench around will immediately affect its calibration. Torque wrenches have even been known to break when dropped.
Using a torque wrench in place of a breaker bar or different type of wrench can affect calibration or even damage the wrench. Treat the torque wrench as a speciality tool, rather than an all-purpose one.
Exceeding the maximum torque rating for a wrench may even break it. If you damage your torque wrench, it may not be able to hold a calibration any longer.
Store the torque wrench low, so if it does fall, it won’t be far enough to cause any significant damage to the calibration. Keep the torque wrench in a climate controlled area. Big shifts in temperature or humidity can affect its calibration.
