Interpreting Engineering DrawingsTech Drawing • 2012-2013 • Mr. Milnes

Basic Types of Lines used in Engineering Drawings

Phantom Line - outline showing an alternate position for a moving part. - Thin line, two short dashes, single long dash.

Center Mark - the center point of a circle or radius (arc). - Appears as a small cross.

Section Line - used to show where material has been cut away to expose the material. - Repeated thin solid lines.

Hidden Line - edges and outlines that are invisible features in a particular view. - Thin width with short dashes.

Object (Visible) Line - the outline or contour of the object being drawn. - Solid Line.

Center Line - the center of a round or cylindrical feature, or the symmetry of a feature. - Thin width, alternating long and short dashes.

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