Chapter 10 Dimensioning
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determine this information is to identify all
object distances as one of three types—overall,
location, and size. These object descriptions are
known as overall, location, and size dimensions.
Overall dimensions provide the overall
object size and tell the manufacturer how large
a piece of material to use to make the object.
Location dimensions indicate where particular
features lie along or within the object. Size
dimensions specify how large the particular
features are, Figure  10-7. As objects become
more complex, identifying these dimensions
becomes more diffi cult. However, if a beginning
drafter can visualize an object, analyze its
features, and think in these terms, he or she can
learn to become very profi cient and consistent
in applying dimensions to drawings.
Proper usage
A
Improper usage
B
Keep leader line
angle within
this range
15°
75°
Do not draw vertical
or horizontal leaders
Goodheart-Willcox Publisher
Figure 10-4. Leaders are used to connect dimensioning information to object features. A—Properly drawn leaders.
Leader lines are drawn at an angle ranging from 15° to 75°. B—Leader lines should never be vertical or horizontal.
Goodheart-Willcox Publisher
Figure 10-5. The leader shoulder connects to the first
or last line of information depending on the placement
of the leader with the note.
Preferred
Length of arrowhead
Avoid
1
_
3
Goodheart-Willcox Publisher
Figure 10-6. Arrowheads are drawn 1/8″ long. The solid arrowhead is generally preferred.
Copyright Goodheart-Willcox Co., Inc.