Engineering Drawings Warmup #1

Lines that are not visible in the current view are represented by dashes. They represent the edges where surfaces meet but are not directly visible. These lines tend to be omitted from drawings unless they are needed to make the drawing clear.

• Continuous/drawing line

• Hidden line

• Center line

• • Symmetry

Parts with holes and symmetrical features can be shown by using this line. This line indicates a circular feature on a drawing and is characterized by its long-short-long alternating line pattern. They can be used to represent: 

• Symmetry

• Paths of motion

• Centers of circles and the axes of symmetrical parts

• Hidden line

• Break line

• Continuous/drawing line

• Center line

This type of drawing show parts as three-dimensional. Vertical lines stay vertical (compared to the front view) and parallel lines are shown at an angle, usually 30 degrees. The object appears as if it is being viewed from above from one corner. The lines that are vertical and parallel are in their true length. This means you can use a ruler and the scaling of the drawing to measure the length.

• Isometric View

• Orthographic View

• 3-D view

• First Angle Projection

These lines are an example of ______

• Dimension Lines

• Center Lines

• Phantom Lines

• Hidden Lines

This is an example of what type of lines?

• Cutting Plane Line

• Phantom Line

• Hidden Line

• Border Line

What type of projection is being displayed?

• First Angle Projection

• Third Angle Projection