iv 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, he has taken several specialized courses in industry, such as the Hobart Institute of Welding Technology and American Welding Society courses. He is a member of the Association for Career and Technical Education and a life member of the American Welding Society. As a coauthor of Modern Welding, he has guided this Goodheart-Willcox book through many revisions to keep it up to date and technically correct in order to maintain its value as an authoritative welding text. He is also a coauthor of Welding Fundamentals. Kevin E. Bowditch is a welding engineer specialist for Subaru of Indiana Automo- tive Inc. His welding experience includes working for two automotive fi rms, two aerospace fi rms, a construction company (building nuclear plants), and a precision sheet metal fi rm. His initial welding training was at the Hobart Institute of Welding Technology. He earned his bachelor’s degree in welding engineering from The 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. While working for one aerospace fi rm, he designed resistance welding and soldering equip- ment, designed special equipment for custom applications, and worked to develop correct welding and soldering schedules for customers. At Subaru, he helps develop and validate welding parameters to make over one billion spot and arc welds per year. Kevin Bowditch joined his father as a coauthor of Modern Welding, beginning with the 1984 edition, and has been a coauthor of Welding Fundamentals since its fi rst edition was published in 1991. Mark A. Bowditch joined the Bowditch team of welding authors in 1998, when he co- authored Oxyfuel Gas Welding with his brother Kevin Bowditch. Mark Bowditch has more than ten years of experience as an educator, holds bachelor’s, master’s, and doctoral degrees, and has taken classes at the Hobart Institute of Welding Technology. In addition to employing his expertise and communication skills in preparing this edition of Modern Welding, he has also assumed responsibility as a coauthor with his brother and father for the 2005 and later revisions of Welding Fundamentals. He is also an offi cer in the United States Air Force Reserves. Reviewers The authors and publisher wish to thank the following industry and teaching professionals for their valuable input into the development of Modern Welding: John G. Acosta WELDTECH Peru, Vermont Brian Bennett Hill College Cleburne, Texas Walker J. Dobry Leyton High School Dalton, Nebraska Alice Obenshain Arkansas Welding Academy Jacksonville, Arkansas Dustin K. Perry Montana State University Bozeman, Montana Mark Thomas Pine Tree ISD Longview, Texas Russell Wahrman Wake Tech Community College Raleigh, North Carolina Dennis Whysong Bedford County Technical Center Everett, Pennsylvania Brian T. Yarrison York County School of Technology York, Pennsylvania