Which statement best defines torque and its importance for fasteners?

• A. Torque is the color coding of fasteners.
• B. Torque is the temperature limit for bolts.
• C. Torque is the turning force applied to a fastener; correct torque ensures proper clamping force, prevents loosening, and maintains joint integrity.
• D. Torque is the torque converter's rotational speed.

Answer: (C)

Torque is the turning force applied to a fastener; when you tighten a bolt or nut, that turning force creates preload, the clamping force that holds the joined parts together. Getting the right torque matters because it sets the correct amount of preload: enough to resist loosening from vibration, thermal cycling, and loads, but not so high that the bolt stretches, yields, or shears threads and damages components. Proper torque ensures the joint stays secure and maintains its integrity over time. It’s also important to remember that lubrication changes how torque relates to preload—lubricated threads reduce friction, so the same torque can produce more clamping force, which is why torque specs often assume a certain lubrication condition. In practice, technicians use a torque wrench to apply the specified torque to each fastener to ensure reliability. The other statements describe color coding, temperature limits, or an unrelated device, which do not define torque or its role in fastening.