What is the preferred method when torqueing bolts with lock tabs: bolt, nut, or both?

• A. Bolt only
• B. Nut only
• C. Both bolt and nut to their specified values
• D. Torque the bolt and the nut at the same time

Answer: (D)

Lock tabs rely on proper preload from both fasteners to prevent rotation under vibration. The best practice is to tighten both the bolt and the nut to their specified torque values as part of the same tightening operation so the locking tab can engage properly. If you only torque one member, the joint may not achieve the required clamp load and the tab may not seat or lock securely, increasing the risk of loosening. After reaching the specified values, bend the tab to lock and verify the assembly is secure.