What is the primary purpose of a torque wrench, and how is its accuracy verified on a ship?

• A. To apply precise torque; verify with calibration block
• B. To measure torque
• C. To tighten as much as possible
• D. To cut threads

Answer: (A)

A torque wrench is built to deliver a specific, controlled amount of torque to a fastener, so the joint is tightened to exactly the intended preload. The tool’s mechanism—whether a click, beam, or digital readout—provides a stop or confirmation at the set torque, preventing under- or over-tightening and helping protect threads and seals.

On a ship, verifying accuracy is about ensuring that the wrench actually produces the torque it’s set to. This is done by checking the wrench against a known reference, typically a calibration block or other torque standard. The wrench is applied to the calibration setup at its set torque, and the output is compared to the known value on the standard. If the reading matches within the allowed tolerance, the wrench is considered in calibration; if not, it is adjusted or retired from service. This keeps critical fastener joints consistent across the fleet, and calibration is performed periodically or after maintenance events as required.

The other descriptions don’t fit as well: a torque wrench isn’t primarily a device for measuring torque in use (that’s what torque-measuring instruments do), it isn’t meant to tighten as hard as possible, and it doesn’t cut threads.