1. business and industrial
2. metals

This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.
Copyright © 2005
by
The Goodheart-Willcox Company, Inc.
Previous Editions Copyright 1997, 1991
All rights reserved. No part of this work may be reproduced, stored, or transmitted
in any form or by any electronic or mechanical means including information
storage and retrieval systems, without the prior written permission of
The Goodheart-Willcox Company, Inc.
Manufactured in the United States of America.
Library of Congress Catalog Card Number 2004054348
International Standard Book Number 1-59070-405-3
1 2 3 4 5 6 7 8 9 – 05 – 09 08 07 06 05 04
The Goodheart-Willcox Company, Inc. Brand Disclaimer: Brand names, company names, and illustrations
for products and services included in this text are provided for educational purposes only, and do not represent or imply endorsement or recommendation by the author or the publisher.
by
William A. Bowditch
Career and Technical Education Consultant, Portage, Michigan
Life Member of the American Welding Society
Member of the Association for Career and Technical Education
and
Kevin E. Bowditch
Welding Engineer Specialist, Subaru-Isuzu Automotive, Inc., Lafayette, Indiana
Member of the American Welding Society
Member of the Association for Career and Technical Education
and
Mark A. Bowditch
Instructor, Saint Mark Lutheran School, Kaneohe, Hawaii
Member of the American Welding Society
Member of the Association for Career and Technical Education
The Goodheart-Willcox Company, Inc. Safety Notice: The reader is expressly advised to carefully read,
understand, and apply all safety precautions and warnings described in this book or that might also be
indicated in undertaking the activities and exercises described herein to minimize risk of personal injury or
injury to others. Common sense and good judgment should also be exercised and applied to help avoid all
potential hazards. The reader should always refer to the appropriate manufacturer’s technical information,
directions, and recommendations; then proceed with care to follow specific equipment operating instructions.
The reader should understand these notices and cautions are not exhaustive.
The publisher makes no warranty or representation whatsoever, either expressed or implied, including but
not limited to equipment, procedures, and applications described or referred to herein, their quality, performance, merchantability, or fitness for a particular purpose. The publisher assumes no responsibility for any
changes, errors, or omissions in this book. The publisher specifically disclaims any liability whatsoever,
including any direct, indirect, incidental, consequential, special, or exemplary damages resulting, in whole or
in part, from the reader’s use or reliance upon the information, instructions, procedures, warnings, cautions,
applications or other matter contained in this book. The publisher assumes no responsibility for the activities
of the reader.
Library of Congress Cataloging-in-Publication Data
Bowditch, William A.
Welding technology fundamentals/by William A. Bowditch and Kevin E. Bowditch.
p. cm.
Includes index.
ISBN 1-59070-405-3
1. Welding. I. Bowditch, Kevin E. II. Title.
TS227.B69.2004
671.5’2—dc22
2004054348
Publisher
The Goodheart-Willcox Company, Inc.
Tinley Park, Illinois
www.g-w.com
2
This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.
Introduction
About the Authors
William A. Bowditch has an extensive teaching and welding background. He has been a teacher,
department head, and supervisor of special needs and vocational programs. In addition to his formal
college training in preparation for teaching, Bill has taken several specialized courses in industry, such
as the Hobart Welding School and American Welding Society courses. He is a member of the American
Vocational Association and a life member of the American Welding Society. As a coauthor of Modern
Welding and Welding Technology Fundamentals, he has guided those Goodheart-Willcox books
through many revisions to keep them up-to-date and technically correct, maintaining their value as
authoritative welding texts.
Kevin E. Bowditch is a welding engineer specialist for Subaru-Isuzu Automotive, Inc. His welding
experience includes working for two automotive firms, two aerospace firms, a construction company
that builds nuclear plants, and a precision sheet metal firm. While working for one aerospace firm,
Kevin designed resistance welding and soldering equipment, special equipment for custom applications,
and worked to develop correct welding and soldering schedules for customers. He has a bachelor’s
degree in welding engineering from Ohio State University and has attended specialized conferences and
courses sponsored by the American Welding Society, American Society of Mechanical Engineers, and
American National Standards Institute. Kevin has been coauthoring Modern Welding with his father
for twenty years, and has been a coauthor of Welding Technology Fundamentals since its first edition,
published in 1991.
Mark A. Bowditch joined the Bowditch authoring team of welding authors in 1998 by coauthoring
Oxyfuel Gas Welding with his brother Kevin. He is an instructor at St. Mark School in Kaneohe,
Hawaii, and holds both a bachelor’s degree and a master’s degree. With over ten years of teaching
experience, he utilizes the expertise and communication skills of a professional educator in his writing.
Mark attended Hobart Welding School in 1997 and is a member of both the American Welding Society
and the Association for Career and Technical Education.
3
Welding Technology Fundamentals is written for secondary and postsecondary students, apprentices,
journeymen, and individuals who wish to learn to weld.
This book covers the equipment and techniques used for the welding and cutting processes most often
employed in industry today. These processes are oxyfuel gas cutting and welding, shielded metal arc welding,
gas metal arc welding, flux cored arc welding, gas tungsten arc welding, and resistance welding.
Welding Technology Fundamentals contains information about welding careers and the physics of
welding. Technical information regarding weld inspection and testing, welder qualification, drawing
interpretation, and welding symbols is also included.
General welding safety is covered in Chapter 1. Safety information and cautions are also written into the
text wherever they apply. Safety information and cautions are printed in red, so that they will stand out.
The text is organized into nine sections. Each section is composed of one or more chapters that describe
processes, explain procedures, or present general information relating to the topic of that section. A section
can be studied independently or in sequence with other sections.
The first section provides general information about welding. The topics presented in these chapters
include welding safety, an overview of welding and cutting processes, a brief discussion of the physics
behind welding, and a close look at the different weld joints and welding positions.
Sections 2–8 present detailed information about welding and cutting processes. This study of processes
begins in Section 2 with a close look at shielded metal arc welding. The subsequent sections present
detailed information about gas metal arc welding, gas tungsten arc welding, plasma arc cutting, oxyfuel
gas processes, resistance welding, and special welding and cutting processes.
The final section discusses technical information that is of practical importance to welders. The topics
covered in these chapters includes interpreting welding symbols, inspecting and testing welds, and
welder certification. The end of the book contains several useful appendices and an extensive glossary of
technical terms.
You may begin your study of welding with any section and progress in any desired sequence from
section to section. However, when you use the Laboratory Manual for Welding Technology Fundamentals,
we recommend that Chapter 33, Welding Symbols, be studied early. Welding symbols are used in the
Laboratory Manual to describe the sample joints and welds for each job assignment. Before attempting any
welding process that uses a pressurized gas, Chapters 20 and 21 should be studied.
Welding Technology Fundamentals is written in an easy-to-read and understandable style. All welding terms
used are those approved by the American Welding Society (AWS). In cases where nonstandard terms are used
by some people in the trade, such terms are often given in parentheses after the correct AWS term. The book is
extensively illustrated with drawings and photographs to show the various processes or welding techniques.
Many tables and charts are provided to help you select the proper variable values required to make a
good weld. Photographs of industrial welding applications have been used, along with photographs of
practice welds in progress. Equivalent SI metric measurement units are shown in parentheses following US
conventional measurements.
You should read the caption accompanying each illustration, since the caption often gives information that
is not covered in the text. Review questions are provided at the end of each chapter to test your knowledge of
the information covered. In most chapters, practice exercises are provided to test your skills as a student
welder in completing various welding tasks.
It is our sincere hope that Welding Technology Fundamentals will help you progress in an organized
manner toward a mastery of the essential welding skills.
William A. Bowditch
Kevin E. Bowditch
Mark A. Bowditch
4
This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.
Chapter Listing
Contents
Chapter 1
Safety in the Welding Shop
Chapter 19
Plasma Arc Cutting
Chapter 2
Welding and Cutting Processes
Chapter 20
Oxyfuel Gas Cutting and Welding: Equipment
and Supplies
Chapter 3
The Physics of Welding
Chapter 4
Weld Joints and Positions
Chapter 5
SMAW: Equipment and Supplies
Chapter 6
SMAW: Equipment Assembly and Adjustment
Chapter 25
Brazing and Braze Welding
Chapter 11
GMAW: Equipment and Supplies
Chapter 12
GMAW: Equipment Assembly and Adjustment
Chapter 13
GMAW: Flat Welding Position
Chapter 14
GMAW: Horizontal, Vertical, and Overhead
Welding Positions
Chapter 15
GTAW: Equipment and Supplies
Chapter 16
GTAW: Equipment Assembly and Adjustment
Chapter 17
GTAW: Flat Welding Position
Chapter 18
GTAW: Horizontal, Vertical, and Overhead
Welding Positions
Personal Safety and Clothing
Fire Hazards
Electrical Hazards
Machinery Hazards
Fumes and Ventilation
Storing Compressed Gases
Lifting
Hazardous Obstacles
Hand and Power Tools
Designated Welding and Cutting Areas
Suffocation Hazards
Welding on Hazardous Containers
Additional Safety Publications
Chapter 23
Oxyfuel Gas Welding: Flat Welding Position
Chapter 8
SMAW: Flat Welding Position
Chapter 10
Surfacing
Chapter 1
Safety in the Welding Shop
Chapter 22
Oxyfuel Gas Cutting
Chapter 7
SMAW: Electrodes
4
Section 1
Introduction
to Welding
Chapter 21
Oxyfuel Gas Cutting and Welding: Equipment
Assembly and Adjustment
Chapter 24
Oxyfuel Gas Welding: Horizontal, Vertical,
and Overhead Welding Positions
Chapter 9
SMAW: Horizontal, Vertical, and Overhead
Welding Positions
Introduction
Chapter 26
Soldering
Chapter 27
Resistance Welding: Equipment and Supplies
Chapter 2
Welding and Cutting Processes
Chapter 28
Resistance Welding: Procedures
The Welding Process
Advantages of Welding and
Cutting Processes
History of Welding
Recent Developments in Welding
and Cutting Processes
Obtaining and Holding a Job in
the Welding Industry
Suggested School Subjects for Success
Personal Traits Sought by Employers
Academic Skills Sought by Employers
Factors That Can Lead to Rejection
for Employment
Factors That May Lead to
Termination from a Job
Chapter 29
Special Welding and Cutting Processes
Chapter 30
Robotics in Welding
Chapter 31
Welding Plastics
Chapter 32
Welding Pipe and Tube
Chapter 33
Welding Symbols
Chapter 34
Inspecting and Testing Welds
Chapter 35
Welder Certification
5
13
14
14
16
16
16
16
17
17
17
17
17
18
18
21
21
22
22
24
24
26
26
26
26
27
Chapter 3
The Physics of Welding
29
Welding Theory
Properties of Metals
Effects of Welding
30
30
31
6
Heat-Treating
Electrical Principles
Units of Measurement
33
33
34
Chapter 4
Weld Joints and Positions
37
Basic Weld Joints
Types of Welds
Joint Geometry
Welding Positions
37
41
42
44
Section 2
Shielded Metal
Arc Welding
Chapter 5
SMAW: Equipment and Supplies
Shielded Metal Arc Welding Principles
SMAW Current and Polarity
SMAW Outfit
Chapter 6
SMAW: Equipment Assembly
and Adjustment
Welding Machine
Electrode and Workpiece Leads
Inspecting the SMAW Outfit
Adjusting the Machine
Chapter 7
SMAW: Electrodes
Covered Electrodes
Electrode Amperage Requirements
51
51
52
53
65
65
67
68
68
71
71
75
Chapter 8
SMAW: Flat Welding Position
81
Preparing to Weld
SMAW Safety Precautions
Striking an Arc
Arc Blow
Running a Weld Bead
Drag Welding
Cleaning the Weld
Reading the Bead
Fillet Welding
Butt Joint
81
82
82
83
85
87
88
88
89
91
Contents
This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.
Contents
Weld Defects
Chapter 9
SMAW: Horizontal, Vertical, and
Overhead Welding Positions
95
Preparing to Weld
Horizontal Welding Position
Vertical Welding Position
Overhead Welding Position
Weld Defects
95
96
99
101
102
Chapter 10
Surfacing
105
Surfacing Principles
Surfacing Electrodes
Surfacing Process
Surfacing with a Shielded Metal Arc
105
106
110
110
Section 3
Gas Metal
Arc Welding
Chapter 11
GMAW: Equipment and Supplies
Gas Metal Arc Welding Principles
Metal Transfer
GMAW Equipment
Protective Clothing and Equipment
Chapter 12
GMAW: Equipment Assembly
and Adjustment
Assembly and Setup
Selecting the Shielding Gas
Selecting the Electrode Wire
Welding Machine Settings
Preparing the Base Metal
Safety Precautions
Shutting Down a GMAW or
FCAW Station
Chapter 13
GMAW: Flat Welding Position
Gas Metal Arc Welding Principles
Holding the Welding Gun
Laying a Weld Bead
Making a Fillet Weld
Welding Aluminum
Contents
150
Chapter 14
GMAW: Horizontal, Vertical, and
Overhead Welding Positions
Out-of-Position GMAW or FCAW
Welding in the Horizontal
Welding Position
Welding in the Vertical Welding Position
Welding in the Overhead
Welding Position
116
116
120
126
129
129
133
135
136
137
138
138
141
141
142
143
145
148
Chapter 18
GTAW: Horizontal, Vertical, and
Overhead Welding Positions
Out-of-Position GTAW
Welding in the Horizontal
Welding Position
Welding in the Vertical
Welding Position
Welding in the Overhead
Welding Position
Welding Other Metals
153
153
154
156
159
Section 4
Gas Tungsten
Arc Welding
Chapter 15
GTAW: Equipment and Supplies
115
Contents
Gas Tungsten Arc Welding Principles
GTAW Equipment
Torches
Cables and Hoses
Shielding Gases
Regulators and Flowmeters
Remote Current Control
Protective Equipment
Chapter 16
GTAW: Equipment Assembly
and Adjustment
Equipment Assembly
Welding Machine Settings
Selecting and Preparing the Electrode
Preparing Metal for Welding
Chapter 17
GTAW: Flat Welding Position
Gas Tungsten Arc Welding Principles
Welding a Bead on Plate
Welding a Bead on Plate with Filler Metal
Welding without Filler Metals
Fillet Welding a Lap Joint
Welding Inside Corner and T-Joints
Welding Butt Joints
Welding Other Metals
Weld Defects
Welding Torches
Protective Clothing
201
201
202
204
205
207
Section 5
Plasma Arc
Cutting
163
163
164
167
168
170
170
171
171
Chapter 19
Plasma Arc Cutting
Plasma Arc Cutting Principles
Plasma Arc Cutting Equipment
and Supplies
Equipment Assembly
Safety Equipment
Preparing to Cut
Cutting Procedure
Plasma Arc Gouging
175
187
190
191
193
194
195
196
197
198
7
211
212
216
216
216
216
220
Section 6
Oxyfuel Gas
Processes
175
178
181
184
187
211
Chapter 20
Oxyfuel Gas Cutting and Welding:
Equipment and Supplies
Oxyfuel Gas Cutting and Welding
Acetylene
Oxygen
Manifolds
Pressure Regulators
Hoses and Fittings
Cutting Torches
8
Chapter 21
Oxyfuel Gas Cutting and Welding
Equipment: Assembly and Adjustment
Assembling the Cutting or
Welding Outfit
Turning on an Oxyacetylene
Cutting or Welding Outfit
Checking for Leaks
Flames
Lighting and Adjusting a Positive
Pressure Cutting Torch
Shutting Down a Positive Pressure
Cutting Torch
Lighting and Adjusting a Positive
Pressure Cutting Torch Attachment
Shutting Down a Positive Pressure
Cutting Torch Attachment
Lighting and Adjusting the Flame—
Recommended Method
Lighting and Adjusting the Flame—
Alternate Method
Shutting down an Oxyacetylene
Welding Outfit
Chapter 22
Oxyfuel Gas Cutting
Oxyfuel Gas Cutting Principles
Oxyfuel Gas Cutting Equipment
Preparing to Cut
Manual Cutting
Cutting Machines and Pattern Tracers
Chapter 23
Oxyfuel Gas Welding: Flat
Welding Position
225
225
227
230
233
234
234
237
Flat Position Welding
Preparing to Weld
Holding the Torch
Describing the Torch Angles
Creating a Continuous Weld Pool
Welding without a Welding Rod
Selecting a Welding Rod
Laying a Weld Bead
239
243
247
247
249
251
252
252
254
254
254
255
255
255
259
259
260
260
260
266
271
271
272
272
273
273
275
277
278
Contents
This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.
Contents
Chapter 24
Oxyfuel Gas Welding: Horizontal, Vertical,
and Overhead Welding Positions
287
Out-of-Position Welding
Welding in the Horizontal
Welding Position
Welding in the Vertical
Welding Position
Welding in the Overhead
Welding Position
Chapter 25
Brazing and Braze Welding
Brazing and Braze Welding Principles
Brazing Filler Metal
Preparing to Braze or Braze Weld
Brazing or Braze Welding Safety
Precautions
Brazing
Braze Welding—Flat Position
Brazing and Braze Welding out
of Position
Chapter 26
Soldering
287
288
293
298
303
304
306
309
309
310
313
317
319
319
320
321
321
322
323
323
Section 7
Resistance
Welding
Chapter 27
Resistance Welding: Equipment
and Supplies
Principles of Resistance Spot Welding
Contents
Chapter 28
Resistance Welding: Procedures
Selecting the Welding Machine
Selecting the Welding Variables
Welding Mild Steel
Welding Aluminum
Projection Welding
Resistance Seam Welding
Welding Procedures
Keyhole
Multiple Weld Passes
Restarting and Ending a Weld
GTAW and GMAW of Pipes and Tubes
329
335
339
339
339
344
344
345
345
388
390
390
391
391
Section 8
Special
Processes
329
The Three-View Drawing
The ANSI/AWS Welding Symbol
Fillet Weld Size
Melt-Through and Backing
Weld Symbols
Weld-All-Around and Field
Weld Symbols
Plug and Slot Welds
Spot Welds
Seam Welds
Chapter 29
Special Welding and Cutting Processes 351
Frequently Used Special Processes
Special Arc Welding Processes
Solid State Welding Processes
Other Welding Processes
Special Cutting Processes
Chapter 30
Robotics in Welding
The Reason for Robots
Types of Industrial Robots
Robotic Welding Systems
Safety around Robots
Chapter 31
Welding Plastics
Plastics in Manufacturing
and Construction
Welding Equipment and Supplies
Plastics-Welding Procedure
Chapter 32
Welding Pipe and Tube
329
Chapter 33
Welding Symbols
Pipes and Tubes
Welding Processes
Types of Joints
Pipe or Tube Welding Positions
Preparations for Welding
351
352
356
357
359
Chapter 34
Inspecting and Testing Welds
363
Reasons for Inspecting Welds
Types of Tests
412
Chapter 35
Welder Certification
427
Codes and Specifications
Employment Considerations
Labor Unions
427
432
432
Appendices
Section 9
Technical
Information
303
317
Soldering Principles
Advantages of Soldering
Soldering Filler Metals
Soldering Fluxes
Hazards of Solders and Fluxes
Containing Lead
Acceptable Solders for Drinking
Water Systems
Preparing to Solder
Soldering Safety Precautions
Procedures for Torch Soldering
Welding Machines
Safety
Contents
395
395
397
401
403
403
404
404
406
411
435
Appendix A, Suggested Welding
Procedure Specification
Appendix B, Suggested Welding
Procedure Qualification Record
Appendix C, Suggested Welding
Performance Qualification Test Record
Appendix D, Millimeter/Inch and
Fraction/Decimal Equivalents
Appendix E, Advantages and
Disadvantages of Various Welding
Processes That Use Consumable
Electrodes
Appendix F, Percentage of Welding
Filler Metal That Becomes Part of a
Completed Weld Joint
Appendix G, Variables That Affect the
Cost of Welding
Glossary of Technical Terms
Index
435
436
438
439
440
440
440
441
456
411
363
364
364
367
371
371
373
375
379
379
381
382
384
386
9
10
Contents
This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.