In GD&T, what is the purpose of a datum feature symbol?

• A. It identifies the surface used to establish a datum.
• B. It indicates the manufacturing step.
• C. It denotes material type.
• D. It specifies finish quality.

Answer: (A)

In GD&T, a datum is a fixed reference used to locate and orient features during measurement. The datum feature symbol marks the surface or feature that will serve as that reference. It identifies which physical surface establishes the datum, so the entire datum reference frame (the primary, secondary, and tertiary datums) is built from that surface or axis. This grounding lets tolerances like position or orientation be interpreted relative to a consistent origin in space. The symbol points to the actual surface used, not to manufacturing steps, material type, or finish.