ESL Resource for Aerospace Pre-Employment: AIR
UNIT 1
Brian Briggs
Community Colleges of Spokane
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What will I learn in this lesson?
 The definition of a blueprint
 Important vocabulary and pronunciation
 The difference between CAD and CAM
 Common parts of a blueprint
 Basics of measurement: parts of an inch
What is a blueprint?
 A blueprint is a plan or
design which describes how
a product should be made.
It shows the measurements,
dimensions, and materials.
In the past, blueprints were
drawn by hand on special
blue paper. Today, many
blueprints are made on a
computer using a special
program called CAD
(Computer Aided Drafting)
Reading Blueprints
 To read a blueprint, it is important to understand the
special vocabulary. You must be able to speak the
language of blueprints. It is a universal language.
Important words to know- Line \ˈlīn\
 Dimension \də-ˈmen(t)-shən\
 Section \ˈsek-shən\
 Process \ˈprä-ˌses\
 Geometric positioning \ˌjē-ə-ˈme-trik pə-ˈzi-shəniŋ\
 Note \ˈnōt\
 Tolerance \ˈtä-lə-rən(t)s\
 Material \mə-ˈtir-ē-əl\
 Lines give a shape to the object and details about it.
 Dimensions give the size and location of parts and
shapes.
 How big are the parts?
 Where do the parts go?
 Sections show how the object looks inside if it were
cut apart.
 Processes explain how the part is to be produced.
 Geometric positioning shows exactly how far apart
objects should be.
 Notes should be clearly lettered (printed).
 Tolerances show exact measurement and dimensions
of finished surfaces.
 Materials are used for making parts. The blueprint
also includes information about the weight, strength,
and hardness. Some common materials are iron, steel,
aluminum, carbon fiber, fiberglass, titanium, and
rubber.
CAD
 Computer-Aided Drafting (CAD) is a computer
program which helps you draft or draw blueprints on a
computer.
CAM
 CAM stands for Computer-Aided Manufacturing.
Things you will see on most
drawings:
 Name of the part
 Quantity (how many are needed)
 Drawing number
 Dimensional tolerance
 Material
Measurement
 Linear or straight line measurement
Measured point
Reference point
Line of measurement
Basic size=
7.5
Inch units
 Drawings might use either inch units, metric units, or
both!
 Fractional parts of an inch
1/64”, 1/32”, 1/16”, 1/8”, 1/4”, 1/2”
 Decimal (mils) parts of an inch
.010”, .050”, .100”, and .500”
Metrics
 Metric dimensions are usually given in millimeters. If
you need to change measurements from one system to
another, please use a conversion table.
Review
 Go to the quiz and see if you understand the
information.
Unless otherwise specified, this work by Air Washington is licensed under a Creative
Commons Attribution 3.0 United States License.