In mechanical drawings, what does a dashed line represent?

A dashed line in mechanical drawings is used to represent hidden lines. These lines indicate features that are not visible from the view presented in the drawing but are present in the object. This is essential for a complete understanding of the design, as it allows engineers and technicians to visualize internal features or edges that cannot be directly seen from the outside. The use of hidden lines ensures clarity in the representation of complex objects, making it easier to understand how components interact or fit together without being misleading about what can be seen.

Other line types serve distinct purposes in mechanical drawings. Dimension lines, for example, are solid lines that show the measurement of objects. Extension lines are used to extend the dimensions to the part, while center lines are often used to indicate the axis of symmetry in an object. Each of these types has unique characteristics and applications in technical drawings, but when it comes to representing features that are not externally visible, the dashed line specifically denotes hidden details.