The calculations and ideas of the engineer must
be transferred to the welder working in the shop or
on a job site. It is usually impractical for an engi-
neer to be present while a weldment is being fab-
ricated. Therefore, the needed information must
be supplied by some method other than verbal
communication. The most concise method for
doing this is through the use of detail drawings.

When drawings are prepared manually, they
are usually made directly on tracing paper or
plastic that is then used for making prints in the
quantities needed. However, the most current
method for the production of prints is through
the use of computers. This latter method is
called Computer Aided Drafting (or Design)
and is abbreviated as CAD. Using the informa-
tion “drawn” with the computer, “hard copies”
of drawings are printed on paper at very high
speeds. The proper use of CAD requires a knowl-
edge of blueprint reading and welding symbols.

(For more information see Unit 27.)

There are three basic elements to be found on
a print: lines, dimensions, and notes (as shown
in Figure 1). Lines show the edges of the object,
aid in dimensioning the object, and are used in
the formation of symbols. Dimensions give sizes

and locations. Notes, giving details of construction not shown by lines, may be in the form of symbols or ab-
breviations. A note that designates the kind of material, machining process, or standard to be used is often
referred to as a specification. Notes or specifications are found adjacent to a view or in a ruled space provided
on the print for this purpose.

A print consists of one or more views, usually the top, front, and right side views of the object. Other views
that may be used to describe the object completely are the left side, back, auxiliary, and bottom views. The
number and type of views to be shown depend on the shape and complexity of the object. A concept of these
views is presented in the units that follow.

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