8
Introduction
Either of these systems of measurement can be used in the two basic types
of measurement. These types are standard and precision.
Standard measurement is widely used in the construction industry, in furni-
ture manufacture, and in sheet metal fabrication. The standard Conventional
unit of measurement is the inch and its fractions.
Precision measurement is used for all manufacturing where close tolerances,
fits, and dimensional control are required. This type of measurement uses
thousandths (1/1000) or ten-thousandths (1/10,000) of an inch.
Directly related to measurement are the names of surfaces and dimen-
sions of a part. These, as reviewed in Figure In-1, are:
✲ Thickness: The smallest dimension of a piece of material. It is usually the
distance between the two sides or faces.
✲ Width: The second smallest dimension of a piece of material. It is usually
the distance between the two edges.
✲ Length: The largest dimension of a piece of material. It is usually the dis-
tance between the two ends.
✲ Side: The largest surface of a material.
✲ Edge: Generally, the second largest surface. For wood, it is the second
largest surface that does not show end grain.
✲ End: Generally, the smallest surface. For wood, it is the surface that shows
end grain.
When giving a part size, convention suggests that the thickness is given
first. Then the width is given and, finally, its length. Therefore, if a part is said
to be 1/2" × 3" × 10", its thickness is 1/2 inch, its width is 3 inches and its
length is 10 inches. Also, if there are no measurement marks such as (") for
inches or (') for feet, the measurement is understood to be in inches.
To review your knowledge, select several items such as your textbook,
workbook, etc. Measure their width, thickness, and length using SI and
Conventional measurements.
Now that you have reviewed safety and measurement, you are ready to
start a challenging study of manufacturing. Good luck!
Length
Side or Edge
Edge
Thickness
Width
End
Figure In-1