Engineers use a special kind of drawings, called engineering drawings, to convey
their ideas and design information about products. These drawings portray vital
information, such as the shape of the product, its size, type of materials used, and
assembly steps. Moreover, machinists use the information provided by engineers or
drafts persons on the engineering drawings to make the parts. For complicated sys-
tems made of various parts, the drawings also serve as a how-to-assemble guide,
showing how the various parts fit together. Most of you will eventually take a semes-
ter-long class in engineering drawing where you will learn in much more detail how
to create such drawings. For now, the following sections provide a brief introduction
to engineering graphical communication principles. We will discuss why engineer-
ing drawings are important, how they are drawn, and what rules must be followed
to create such drawings. Engineering symbols and signs also provide valuable infor-
mation. These symbols are a “language” used by engineers to convey their ideas, solu-
tions to problems, or analyses of certain situations. In this chapter, we will also discuss
the need for conventional engineering symbols and will show some common symbols
used in civil, electrical, and mechanical engineering.
16.1 Importance of Engineering Drawing
Have you ever had an idea about a new product that could make a certain task easier? How did
you get your idea across to other people? What were the first things you did to make your idea
clearly known to your audience? Imagine you are having a cup of coffee with a friend, and you
decide to share your idea about a product with her. After talking about the idea for a while, to
clarify your idea, you will naturally draw a picture or a diagram to show what the product would
look like. You have heard the saying “a picture is worth a thousand words”; well, in
engineering, a good drawing is worth even more words! Technical drawings or engineering16.1 Importance of Engineering Drawing 507
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