A shaft has a tolerance of 0.500 ± 0.005 inches and a hole has a tolerance of 0.500 ± 0.003 inches. Is a clearance fit guaranteed?

• A. Yes
• B. No
• C. Only if temperature-controlled
• D. Only with larger hole

Answer: (B)

The ability to guarantee a clearance depends on whether the hole is always bigger than the shaft, even in the worst-case sizes. The shaft can vary from 0.495 to 0.505 inches, while the hole can vary from 0.497 to 0.503 inches. For a guaranteed clearance, the smallest hole would have to exceed the largest shaft, but 0.497 is not greater than 0.505. In the worst case, the shaft could be 0.505 and the hole only 0.497, causing an interference of 0.008 inches. Because the size ranges overlap, you cannot guarantee a clearance with these tolerances. To guarantee clearance, the tolerances would need to ensure hole minimum > shaft maximum (or otherwise adjust sizes).