What is the typical working range of a torque wrench?

In the context of torque wrenches, the typical working range often falls between 20% and 90% of the tool's full scale. This range allows for both accurate readings and sufficient torque application without risking damage to the wrench or the bolt being turned.

Torque wrenches operate best within this range because operating outside of it can lead to inaccuracies. For example, using the wrench at very low settings can result in a less reliable torque application due to potential slack in the mechanism. On the other hand, using the wrench at or near its maximum capacity can also introduce errors or potentially damage the tool.

This working range is well established in mechanical and engineering practices, ensuring that the torque applied is both precise and safe for most applications. Thus, the option indicating a working range of 20-90% is the most appropriate representation of how torque wrenches are designed to function effectively.