What is the purpose of a torque-limiting device and where is it used?

• A. To prevent over-tightening; used on critical fasteners where excessive torque could cause damage.
• B. To increase the torque beyond specification.
• C. To measure torque after installation.
• D. To lubricate fasteners.

Answer: (A)

Preventing over-tightening by limiting the applied torque to a preset value is the purpose of a torque-limiting device. It uses a mechanism that slips or signals when the preset torque is reached, so the fastener gets the correct clamping force without risking thread damage, bolt failure, or distorted parts. This is important on fasteners that are critical to safety or performance, where applying too much torque could cause serious damage. It isn’t meant to increase torque, it doesn’t measure torque after installation, and it doesn’t lubricate fasteners.