Which of the following is necessary to control location?

• A. Dyamaic, Concentricity, and Symmetry
• B. Position, Concentricity, and Symmetry
• C. Angle, Diameter, and Location
• D. Precision, Alignment, and Orientation

Answer: (B)

The correct choice emphasizes the essential geometric controls needed to define and constrain the location of a feature on a part.

Position is crucial as it directly specifies the exact location of a feature in a defined coordinate system, allowing for tolerance to ensure that the feature can fit and function as intended. Concentricity helps ensure that features are situated along a common axis, which is especially critical for holes that must align with rotating parts. Symmetry assists in ensuring that features are evenly placed, thereby ensuring that they have the same distance to a reference plane or axis, which can further aid in achieving a desired location with respect to other features.

The inclusion of these three controls—Position, Concentricity, and Symmetry—provides a comprehensive approach to controlling the spatial arrangement of features, ensuring that they meet functional requirements effectively.

In contrast, the other choices either mention terms that are not directly associated with controlling location in the context of GD&T or combine concepts that do not provide an adequate framework for defining the precise location required for parts.