This book comprehensively examines every aspect of resistance welding, from metallurgy and fundamental physical processes, such as electrothermal processes and discontinuities, to mechanical testing, process monitoring and control, weld quality and inspection, expulsion, and numerical simulation. The authors consider the influence of mechanical characteristics of welding machines and emphasize statistical design, analysis, and inference in resistance welding research, enabling students to conduct their own investigations. They present state-of-the-art research results from their own studies as well as from other leading experts, and the text's many examples are derived from real experiments. Case studies and nearly 300 figures illustrate the concepts.