What is the true position in GD&T?

• A. The theoretically exact location of a feature relative to datums
• B. The manufacturing tolerance
• C. The theoretical maximum size
• D. The surface roughness requirement

Answer: (A)

True position specifies the theoretically exact location of a feature relative to the datum reference frame. It is the ideal spot the feature would occupy if there were no manufacturing variation. A positional tolerance then defines how far the real feature is allowed to deviate from that exact spot, with the tolerance zone oriented and sized by the datums. This makes true position the precise standard for where a feature should sit in relation to the datum structure, which is crucial for proper fit and function in assemblies.

Other GD&T aspects address different properties. Size tolerance controls how big or small the feature can be, not where it sits. The theoretical maximum size is about an upper limit on size, not location. Surface roughness concerns texture of the surface, not placement. So true position is specifically about the exact location relative to datums, not about size or surface finish.