When an extension is installed toward the handle, which statement correctly describes how to determine the applied torque?

• A. Use the same torque setting without correction
• B. Apply the corrected torque using the appropriate formula
• C. Increase torque by a fixed amount for extensions
• D. Ignore the extension and proceed

Answer: (B)

When the extension is added toward the handle, the effective lever arm length of the torque wrench increases, so the torque actually applied to the fastener is higher than what the wrench reads. To get the desired torque at the fastener, you must use a corrected setting that accounts for the longer lever.

The relationship is T_actual = T_indicated × (L + E) / L, where L is the wrench’s original lever length and E is the extension length. If you know the target torque at the fastener and you want to set the wrench accordingly, use T_indicated = T_target × L / (L + E).

For example, with a wrench length L of 10 inches and an extension E of 2 inches, aiming for 100 ft-lb at the fastener, you would set the wrench to 100 × 10/12 ≈ 83.3 ft-lb. The actual torque at the fastener becomes 83.3 × 12/10 ≈ 100 ft-lb.