What is the mandrel deflection limit?

• A. 5%
• B. 6%
• C. 7%
• D. 8%

Answer: (B)

Mandrel deflection limit is the maximum amount the mandrel is allowed to move off the intended axis during bending to keep the part from developing defects. If the mandrel deflects too much, it can cause wall thinning, out-of-roundness, or an inconsistent bend.

Six percent is used here because it strikes a practical balance: it provides enough tolerance to accommodate tool wear and measurement variation, while still limiting deflection enough to prevent noticeable defects in the final part. Values that are tighter (like five percent) would make manufacturing more difficult and increase scrap, while looser limits (like seven or eight percent) would raise the risk of defective bends.