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, 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 Association for Career and Technical Education and a life member of the American Welding Society. As a coauthor of Modern Welding and Welding 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 spe- cialist for Subaru of Indiana Automotive, Inc. His welding experience includes working for two automotive fi rms, two aerospace fi rms, a construction company that builds nuclear plants, and a precision sheet metal fi rm. While working for one aerospace fi rm, Kevin designed resistance welding and soldering equipment, special equip- ment for custom applications, and worked to develop correct welding and soldering schedules for customers. He earned his 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 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, published in 1991. Mark A. Bowditch joined the Bowditch team of welding authors in 1998 by coauthoring Oxyfuel Gas Welding with his brother Kevin Bowditch. Since that time, Mark Bowditch has coauthored multiple editions of Oxyfuel Gas Welding, Modern Welding, and Welding Fundamentals. He has more than 10 years of experience as an educator, and holds bachelor’s, master’s, and doctoral degrees. Mark Bowditch attended Hobart Welding School in 1997 and is a member of both the American Welding Society and the Association for Career and Technical Education. He is also an offi cer in the United States Air Force Reserves.