Which tool is used to apply a precise torque to fasteners during assembly?

• A. A torque wrench is used to accurately apply a specified torque to fasteners.
• B. A micrometer is used to accurately apply a specified torque to fasteners.
• C. A dial indicator is used to measure torque.
• D. A screwdriver is used to apply a torque.

Answer: (A)

Applying a precise torque to fasteners ensures the correct preload and prevents damage from under- or over-tightening. A torque wrench is designed to set a specific torque value and indicate when that value is reached, giving you a consistent, controlled fastening. The other tools aren’t built to control or measure torque: a micrometer measures dimensions, not rotational force; a dial indicator gauges displacement or runout; and a screwdriver relies on manual effort with no torque reference, so the applied torque can vary widely. Torque wrenches come with adjustable settings and often a click or other cue when the desired torque is reached, providing repeatable results across fasteners. This is why it’s the best choice for applying precise torque during assembly.