What is the term for the line used to indicate the extent of a dimension (locations, length, width, or thickness)?

What is the term for the line used to indicate the extent of a dimension (locations, length, width, or thickness)?

• A. Section line
• B. Leader line
• C. Dimension line
• D. Center line

Answer: (C)

The dimension line is the line that shows the extent of a measurement such as locations, length, width, or thickness. It runs between extension lines from the features being measured and has arrowheads at its ends; the numeric value of the dimension is written near or above it. This setup clearly communicates exactly how far apart those features are.

This differs from a section line, which is used to reveal interior features by cutting through the object; a leader line, which attaches notes or callouts to a feature rather than indicating size; and a center line, which marks the axis of symmetry or center of a circular feature rather than a measured distance. For example, to specify a width of 3 inches, you’d have extension lines from the two faces, a dimension line between them with arrowheads at each end, and “3 in” labeled above.