What's the most accurate way to enter force information for using a manual torque wrench?
It’s a common mistake to simply record the torque wrench setting for the force value in a job assessment. For an accurate measurement, you must account for the length of the torque wrench using the following calculation: Force (F) = Torque (T) / Wrench Length (L).
- Force (F) = force applied to the wrench in newtons (N)
- Torque (T) = rotational force applied to the object in newton-meters (Nm)
- Wrench Length (L) = distance from pivot point to point where force is applied in meters (m)
For example, if applying torque of 50 Nm with a wrench that is 0.5 m long, the force required would be calculated this way: F = 50 Nm/0.5 m = 100 N.
To convert newtons to pounds or kilograms of force for entry into the software, use the following:
- N/4.448 = lbf
- N/9.807 = kgf
You can also use lb-ft or lb-in:
- Force (F) = force applied to the wrench in pounds (lb)
- Torque (T) = rotational force applied to the object in foot-pounds (lb-ft)
- Wrench Length (L) = distance from pivot point to point where force is applied in feet (ft)
For example, if applying torque of 20 lb-ft with a wrench that is 2 feet long, the force required would be calculated this way: F = 20 lb-ft/2 ft = 10 lb. If the torque is specified in inch-pounds, measure the wrench length in inches.
