Introduction to Engineering
Dimensioning - 2
Agenda
 Understand the principles of good
dimensioning practice
 Apply the standard dimensioning practices for
mechanical drawings
1
Dimensioning
 Orthographic and isometric views define the
shape and general features of the object
 Dimensioning adds information that specifies
Size of the object
Location of features (e.g. holes)
Characteristics of features (e.g. depth and diameter of
hole)
 Dimensions also communicate the Tolerance (or
accuracy) required
2
Dimensions include notes for construction
or manufacturing
Type of material to use
How smooth or rough the surface
should be
Etc…
3
Standards for Dimensioning
Defined Standards have been developed
 Available from ANSI
 American National Standards Institute
4
Scaling vs. Dimensioning
Drawings can be of different scales, but
dimensions are ALWAYS at full scale.
5
Dimensioning - Terminology
(Study 4.2.1
and 4.2.2 of
text,
carefully)
6
Dimensioning - Text Height and Standard
Configurations
.25 in
.375 in
7
Dimensioning Basic Shapes -Assumptions
Perpendicularity
Symmetry
8
Dimensioning Basic Shapes
-Simple Shapes
Rectangular Prism (Principal Dimensions:
H,W,D)
D
W
H
9
Video on Dimensioning
10
Assignment
Drawing #2
11