Mechanical drawings


When interpreting a mechanical drawing you will notice that there are a variety of line types and styles used on the drawing. This includes different weights of lines (how dark). As well as the outline of the object being drawn, there is a range of other lines used as follows:

  1. Leader line
  2. Outline
  3. Hidden outline
  4. Extension line
  5. Dimension line
  6. Centre line.

The line types listed above are included (highlighted with blue colour) in the following sample diagram.


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Sample diagram showing common line types

Mechanical diagram with common line types