Introduction Modern Welding is an authoritative and technically correct text written for use by students and teachers in secondary schools, colleges and universities, and technical and trade schools. It is also suitable for use by indi- viduals who wish to learn independently about contemporary processes and techniques used in welding. Modern Welding will provide you with an understanding of virtually all the welding and cutting processes used in production and repair today. This book covers the theory, fundamentals of operation, equipment used, and techniques recommended for all of the welding and cutting processes that are commercially used. The many tables and charts that are included in Modern Welding provide information regarding recommended settings for the variables involved in the various welding processes. These tables include the recommended gas pressures, tip sizes, welding speeds, amperage and voltage settings, wire feed rates, electrode sizes, inert gas selections, and much, much more. General shop safety, safety attitudes, and specifi c welding shop safety practices are covered in Chapter 1. Safety information and cautions are also printed in red throughout the text, wherever they apply. Chapters 2 and 3 cover print reading and the interpretation of the American Welding Society welding symbols found on welding prints. Chapter 4 is an overview of welding and cutting processes that are covered in detail later in the book. The remainder of the text is divided into eight sections, each covering a different welding process or group of related welding processes. Chapter 33 covers the subject of getting and holding a job in the welding industry. Technical information that may be required while working in the welding industry is included in Chapter 34. An extensive Glossary of Welding Terms is provided at the end of the book. Modern Welding may be studied in order from Chapter 1 to Chapter 34, or it may be used to study welding processes in any desired order. Each section stands alone, and does not rely on previously acquired knowledge. Modern Welding is extensively illustrated with full-color and black-and-white photographs, as well as drawings that have been color-coded to help you better understand each welding process and its equipment. All fi gure captions should be read, since they may contain details that are not included in the text. Measurements are generally shown in dual form: US Customary followed by SI Metric. Welding terms used throughout conform to the usage in the AWS Standard A3.0:2010, Standard Welding Terms and Defi nitions. Nonstandard or “trade” terms, when given, are clearly identifi ed. The topics covered in Modern Welding are presented in a logical sequence designed to make learning and teaching the technology of welding easier and more effective. William A. Bowditch Kevin E. Bowditch Mark A. Bowditch 3