Figure 13-4.--Bill of material.
drawn to a scale, the actual size shown on paper will be
--Center lines are thin lines made up of long and
larger or smaller than the true item. Therefore, the
short dashes, alternately spaced and consistent
actual dimensions are indicated by whole numbers,
fractions, decimals, or angles. You will use the
--Dimension lines are thin lines ending with
dimensions on prints to accurately locate, lay out, and
arrowheads at each end.
manufacture an item to true size as shown on a
--Leader lines are thin lines ending with an
blueprint. Dimensions are also used to outline shapes
of objects on prints. The six major kinds of dimensions
arc as follows (fig. 13-6):
-- A phantom line is a medium series of one long
dash and two short dashes, evenly spaced and
ending with a long dash.
Conventional dimensions give the overall
dimensions (length, width, and height) of an
-- A stitch line is a medium series of short dashes,
evenly spaced and labeled.
--Thin solid ruled lines with freehand zig-zag
Base line dimensions give all the dimensions
indicate a break (long).
of an object and are indicated in relation to a
--Thick solid freehand zig-zag lines indicate a
designated base line or center line. Base line
dimension is used to mark precision parts on a
direction in which a section or plane is viewed
Chamfer and bevel dimensions indicate linear
and angular dimensions of the edges of an
Radius and arc dimensions indicate circular or
Dimensions on blueprints are used to indicate sizes
and locations. Since items shown on a blueprint are
rounded portions of an object.