What delineates a surface feature in technical drawing?

A leader line is used in technical drawing to indicate a surface feature by connecting a note or reference to a specific point on an object. This line helps clarify the exact location of the feature being referenced, making it easier for viewers to understand which part of the drawing is associated with the descriptive note. Leader lines can include arrows or other indicators to point directly to the relevant feature, thus enhancing the clarity and communicative power of the drawing.

While dimension lines, extension lines, and construction lines serve important functions in conveying measurements, boundaries, and reference points, they do not specifically delineate or highlight a surface feature as effectively as a leader line. Dimension lines indicate sizes, while extension lines show the limits of a measurement, and construction lines are used for guides and layout purposes without conveying specific features directly. Therefore, the leader line is the most appropriate choice for identifying surface features in technical drawings.