What is true position?

What is true position?

• A. The location of a feature relative to the datum reference frame.
• B. The depth of a hole.
• C. The surface roughness requirement.
• D. The orientation of a feature relative to the part edge.

Answer: (A)

True position controls where a feature is located in relation to the datum reference frame. It defines a tolerance zone for the feature’s location (for a hole, the axis must lie within a cylindrical zone whose axis is defined by the datums and whose diameter equals the position tolerance). This is about location in space, not how deep the feature is, how rough its surface is, or how it’s oriented. Depth is a separate dimensional or depth tolerance, not true position. Surface roughness is a finish specification, not a geometric location constraint. Orientation-related controls (like how a feature faces or is angled relative to a edge or datum) are handled by perpendicularity, angularity, or profile/ orientation tolerances, not true position.

True position controls where a feature is located in relation to the datum reference frame. It defines a tolerance zone for the feature’s location (for a hole, the axis must lie within a cylindrical zone whose axis is defined by the datums and whose diameter equals the position tolerance). This is about location in space, not how deep the feature is, how rough its surface is, or how it’s oriented.

Depth is a separate dimensional or depth tolerance, not true position. Surface roughness is a finish specification, not a geometric location constraint. Orientation-related controls (like how a feature faces or is angled relative to a edge or datum) are handled by perpendicularity, angularity, or profile/ orientation tolerances, not true position.