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144 Part III: Inspection and Test
2. TERMINOLOGY AND SYMBOLS
Define and interpret drawing views, details,
etc., for product specifications or other
controlling documents, and define and use
various terms and symbols from the ASME
Y14.5M Standard. (Application)
Body of Knowledge III.A.2
Part III.A.2
The Y14.3-2003 Multiview and Sectional View Drawings standard published by ASME
establishes the requirements for creating orthographic views for item description.
The standard includes the multiview system of drawing, selection, and arrangement
of orthographic views, auxiliary views, sectional views, details, and conventional
drawing practices. This allows engineers to view different angles and
look at a more detailed picture of the item (ASME 2003). The different views and
symbols can be interpreted to extract the required information and the specifications
of the item. For example, orthographic views will show a top view, a front
view, and a right side view. One view will not be sufficient to describe the item in
detail, additional views are required. The number of orthographic views needed
to describe an object fully depends on the complexity of the object. For example,
a simple metal washer can be fully described using only one orthographic view;
however, an extremely complex object may require as many as six views (top, front,
left side, right side, back, and bottom). Most objects can be sufficiently described
using three views: top, front, and right side as shown in Figure 14.9.
The symbols on engineering drawings have different representations based
on the ASME standards. For example, the different line styles each have their own
interpretation. Figure 14.10 shows the different line symbols that are used in engineering
drawings.
Other symbols that are used in a feature control frame to specify a feature’s
description, tolerance, modifier, and datum(s) are shown in Table 14.1.
Top view
Front view
Right side view
Figure 14.9 Top, front, and right side views of an item.