For what purpose is a torque wrench primarily used?

A torque wrench is specifically designed to apply a precise amount of torque to fasteners, such as bolts and nuts. This is crucial in various mechanical and engineering applications where the integrity and safety of a joint depend on the correct tension of the fasteners. By ensuring that a fastener is tightened to the manufacturer’s specified torque setting, a torque wrench helps prevent issues like joint failure due to over-tightening, which can cause strain and damage, or under-tightening, which may lead to loosening during operation. This precision in fastening is especially important in aviation and automotive industries, where safety and reliability are paramount.

The other options pertain to different measurement or calibration tools that serve distinct purposes, which do not align with the function of a torque wrench.