If you need to apply 35 in-lbs of torque and the setup uses an 8-inch length with an extension of -2 inches, what torque setting is required?

• A. 35 in-lbs
• B. 28 in-lbs
• C. 46.7 in-lbs
• D. 60 in-lbs

Answer: (C)

When you change the effective lever length, the torque at the fastener changes if you keep the same wrench setting. The wrench is calibrated for a certain handle length, so the actual torque you deliver scales with the ratio of the lever you’re using to the wrench’s calibrated length: T_actual = T_setting × (Leffective / Lw).

Here, the calibrated length is 8 inches and the extension reduces the effective length to Leffective = 8 − 2 = 6 inches. To get 35 in-lbs at the fastener, solve for the setting: T_setting = 35 × (8 / 6) ≈ 46.7 in-lbs.

So, set the torque wrench to about 46.7 in-lbs to achieve 35 in-lbs at the fastener with the shorter lever.