What are thin lines with arrowheads used to indicate dimensions called?

Thin lines with arrowheads that are used to indicate dimensions are known as dimension lines. These lines serve a critical function in technical drawings by providing precise measurements of the size and location of features on an object. The arrowheads at each end of a dimension line point to the points being measured, helping to clearly communicate the extent of the dimension.

Dimension lines are an essential part of engineering drawings and blueprints, as they ensure that anyone reading the drawing can accurately interpret the dimensions without confusion. This clarity is crucial for manufacturing and fabrication processes, where precise measurements are necessary to produce parts that fit together correctly.

In contrast, center lines are used to represent the centers of circles or symmetry in objects, hidden lines show features that are not visible from the current view, and object lines depict the edges and outlines of the objects in the drawing. Each type of line serves a specific purpose in conveying information on a technical drawing, but the defining characteristic of dimension lines is their role in explicitly indicating the size and shape of components.