Read Between the Lines
In technical drawing, lines are very essential. In fact, all graphic representations are illustrated through different types of lines. If you come across a technical drawing, you would not be able to get the idea it is trying to communicate if you do not know how to make the meaning out of the lines.
There are five basic types of lines used in technical drawing. These are as follows:
Construction Lines
These lines are used as the starting point of technical drawing. Aside from this, construction lines are also used to connect objects and to move dimensions or lines to another part of the drawing. They are erased after the drafters have lay out the visible lines. In CAD, these lines are simply turned off.
Visible Lines
From the name it self, these lines are visible in the final draft. All together, they form the shape of the object that drafters and designers want to convey.
Dimension Lines
The dimension lines are lines that illustrate the measurement of a specific portion of the object.
Hidden Lines
Even though they are called hidden, they are still visible in the final draft. These lines demonstrate the part of the object that cannot be seen from a certain view. Hidden lines are represented by dotted lines.
Center Lines
These lines are used to illustrate the center of a circle or an arc in a technical drawing.
The illustration below is an example of these lines in a Computer-aided Design and Drafting program.
Construction lines are in red.
Visible lines are in black.
Dimension lines are in blue.
Hidden lines are in green.
Center lines are in light blue.