What is the primary purpose of a torque wrench?

• A. To measure electrical resistance
• B. To tighten fasteners to a specified torque
• C. To cut metal
• D. To test battery voltage

Answer: (B)

A torque wrench is designed to apply a precise twisting force to fasteners. That precise torque ensures the clamp load is correct—enough to hold parts together securely, but not so much that threads are stripped or bolts are overstretched. If a fastener is under-torqued, it can loosen; if it’s over-torqued, it can cause damage. By setting the wrench to the required value, you limit the force and stop as soon as that setting is reached, often indicated by a click or beep. This consistency is essential in bus maintenance for items like wheel lugs, engine bolts, and suspension components, helping keep systems safe and reliable. Different types exist (beam, click, digital), but their job is the same: control tightening force. They aren’t used for other tasks like measuring electrical resistance, cutting metal, or testing voltage, which are handled by other tools such as multimeters or saws.