Parallel Practices, Continued
Partial views
Sectional views
Revolved or
removed
sections
Angles
Dimensioning
Lettering
Use a partial view if necessary to clarify the description of an object. Use a
break line or the contour of the object itself to define the limitations of the
partial view. Do not place break lines too near a visible or hidden line. For
symmetrical objects, consider using a sectional view.
You may use any type of sectional view in a multiview projection so long as
its purpose is to clarify the features of an object. A cutting-plane line
indicates the part being viewed with the arrowhead showing the direction of
sight.
You should use removed or revolved views on multiview projections to
clarify an objects profile. Removed sections may be partially removed and
rotated toward the plane of projection or they may be a separate revolution of
the entire object aligned with the primary view as in an aligned section.
Removed views are indicated by a viewing-plane line with arrowheads
indicating the direction of sight. The viewing-plane shows a portion of the
object as it would appear if removed from the object.
In multiview projections, angles on the surface of an object that is parallel to
the plane of projection appear in true size and shape. Angles on surfaces not
parallel to the plane of projection appear foreshortened. Convert angle into
linear measurements before drawing.
All dimension lines, extension lines, and arrowheads must lie in the planes of
the object to which they apply. Place dimensions outside the object outline
except when it helps to clarify. Align dimensions and notes shown with
leaders to the bottom of the drawing. Notes without leaders should also be
aligned with the bottom of the drawing. You may use either aligned or
unidirectional methods of dimensioning. Use either whole numbers and
fractions, decimal, or metric units of measure to mark dimensions on a
drawing.
Lettering on multiview projections is single-stroke gothic. Lettering is
vertical in orientation.
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