Which tool is used to tighten a nut or bolt to a specified amount of pressure?

A torque wrench is specifically designed to measure and apply a precise amount of torque to fasteners such as nuts and bolts. This tool ensures that the fasteners are tightened to the manufacturer's specifications, which is critical in preventing damage from over-tightening or ensuring that the components remain securely fastened under loads.

The precision aspect of a torque wrench allows it to avoid the trial-and-error approach that other tools might require, as it's calibrated to indicate when the desired torque level has been reached. This capability is particularly important in applications such as automotive work, construction, and machinery assembly, where the integrity of joinery can significantly impact safety and functionality.

In contrast, a socket wrench is typically used for turning nuts and bolts but does not measure the torque being applied, making it less suitable for tasks where specific torque is crucial. An adjustable spanner can fit various sizes of nuts and bolts but also lacks the accuracy in torque measurement. An impact driver is used for driving screws and bolts with high rotational force, but it does not provide the control needed for precision torque. Hence, the use of a torque wrench is essential for tasks requiring tight fastening to exact specifications.