If a crankshaft originally measured 3.499 to 3.500 inches and is machined by removing 0.010 inches, what is the resulting diameter range?

If a crankshaft originally measured 3.499 to 3.500 inches and is machined by removing 0.010 inches, what is the resulting diameter range?

• A. 3.509 to 3.510 inches
• B. 3.480 to 3.481 inches
• C. 3.489 to 3.490 inches
• D. 3.495 to 3.496 inches

Answer: (C)

When you remove material through machining, the diameter gets smaller by the exact amount you remove. Start with the original range: 3.499 to 3.500 inches. Subtract 0.010 from both ends to account for the material removed: 3.499 − 0.010 = 3.489 and 3.500 − 0.010 = 3.490. The resulting diameter range is 3.489 to 3.490 inches. Other options would require increasing the size or changing the amount removed, which isn’t what happens when you machine away material.

When you remove material through machining, the diameter gets smaller by the exact amount you remove. Start with the original range: 3.499 to 3.500 inches. Subtract 0.010 from both ends to account for the material removed: 3.499 − 0.010 = 3.489 and 3.500 − 0.010 = 3.490. The resulting diameter range is 3.489 to 3.490 inches. Other options would require increasing the size or changing the amount removed, which isn’t what happens when you machine away material.