If you set TW to 35 in-lbs with L = 8 inches and E = 2 inches reverse extension, what is the actual torque TA?

If you set TW to 35 in-lbs with L = 8 inches and E = 2 inches reverse extension, what is the actual torque TA?

• A. 26.25 in-lbs
• B. 35 in-lbs
• C. 21.9 in-lbs
• D. 28.8 in-lbs

Answer: (A)

When a reverse extension is used on a torque wrench, the effective lever arm is shortened, so the actual torque applied is less than the indicated torque. The relationship is TA = TW × (L − E)/L, where TW is the indicated torque, L is the handle length, and E is the extension length in reverse. Plugging in the numbers: L − E = 8 − 2 = 6 inches, so (L − E)/L = 6/8 = 0.75. Then TA = 35 in-lbs × 0.75 = 26.25 in-lbs. Therefore, the actual torque is 26.25 in-lbs.

When a reverse extension is used on a torque wrench, the effective lever arm is shortened, so the actual torque applied is less than the indicated torque. The relationship is TA = TW × (L − E)/L, where TW is the indicated torque, L is the handle length, and E is the extension length in reverse.

Plugging in the numbers: L − E = 8 − 2 = 6 inches, so (L − E)/L = 6/8 = 0.75. Then TA = 35 in-lbs × 0.75 = 26.25 in-lbs. Therefore, the actual torque is 26.25 in-lbs.