Why might a torque wrench specify a torque range?

A torque wrench specifies a torque range primarily to ensure proper functioning of the fastener. Fasteners such as bolts and nuts are designed to be tightened to a specific torque level to achieve the desired clamping force. If fasteners are under-tightened, they may not hold components together effectively, leading to mechanical failure. Conversely, over-tightening can strip threads, damage components, or exceed the material limits of the fastener, potentially resulting in catastrophic failures. A specified torque range helps mechanics apply the right amount of force, ensuring that the fasteners perform as intended without compromising the integrity of the assembly.

While fasteners do need to be tightened within a range to avoid issues such as stripping (the first choice) or to accommodate various sizes of sockets (the third choice), the main objective is always to maintain the functionality of the joint being secured. Limiting the tool's use to certain conditions (the fourth choice) is not the primary purpose of specifying a torque range; instead, the focus is on guaranteeing that the fasteners perform effectively under operational conditions.