What is the purpose of boxing basic dimensions?

• A. To indicate a tight tolerance on size.
• B. Boxed basic dimensions indicate exact values used to locate features.
• C. To show maximum material condition.
• D. To specify manufacturing process notes.

Answer: (B)

Boxed basic dimensions provide exact target values used to locate features, not a tolerated size themselves. In GD&T, these dimensions define the true position (or other locating coordinates) relative to datum features. The actual part must lie within the geometric tolerance zone defined for that feature, using the boxed values as the precise reference points. Because they are boxed, they are not themselves tol eranced; instead, tolerances appear in geometric tolerance frames attached to the features. This is why boxed basic dimensions are about locating features with exact coordinates, while other choices refer to toleranced sizes, material conditions, or process notes.