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?

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.

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.