How do you determine if a fastener has been properly torqued after installation?

• A. Visually inspect only.
• B. Re-torque with calibrated wrench, check for proper seating, ensure no binding; inspect for signs of looseness or failure.
• C. Weigh the bolt to assess tightness.
• D. Lubricate threads and assume torque is correct.

Answer: (B)

The main idea is that confirming proper torque isn’t about how the fastener looks, but about the actual preload it creates and how the joint sits together. To verify this, you re-torque with a calibrated torque wrench to obtain the specified clamping force, then check that the joint seats evenly and that nothing is binding. This sequence ensures the fastener is pulling the parts together with the correct tension and that the mating surfaces are in full contact as intended. It also helps catch issues like cross-threading, galling, or misalignment that can hide behind a clean appearance.

After tightening, inspect for signs that the connection remains secure, such as absence of movement, no loosening indicators, and no damage to threads or the bolt head. This final check confirms that the preload is maintained under real conditions and that the joint will tolerate service loads.

Visual inspection alone can miss under- or over-tightening; weighing a bolt isn’t a valid measure of tightness, and lubricating threads while assuming the torque is correct obscures the true preload. Using a calibrated wrench and verifying seating and binding gives a reliable, repeatable measurement of proper torque.