What is the recommended usable range of a torque wrench?

The recommended usable range of a torque wrench is often cited as 25%-75% of its full scale. This range is optimal because it ensures the most accurate and consistent torque readings. When using a torque wrench, operating outside of this range, especially at or near the extreme ends (0%-10% or 90%-100%), can lead to inaccurate torque applications due to potential mechanical slack or reduced calibration reliability.

Using a wrench within the 25%-75% range allows the internal mechanism to function effectively and reliably, providing a more precise and repeatable torque application. This ensures that the fastening is executed appropriately, which is critical in applications requiring specific torque specifications. Additionally, working within this mid-range helps to prolong the life of the tool and maintain its accuracy over time, reducing the risk of damage or wear.

This range is widely accepted in both industrial and mechanical contexts, making it a best practice for professionals in the field, ensuring safety and longevity of both the tool and the components being assembled.