The first interpretive report on electron-beam welding, WRC Bulletin 100, covered the early pioneering stages of the process and the men who refined theories, described their principles, and finally built laboratory equipment.In addition, the authors covered the materials (steel and aluminum), the limited applications, and the equipment which were available during the processs growing infancy.This report covers the advancements made in understanding the process, equipment with numerical control, tooling improvements and simplicity, wider use of the process in no and/or medium vacuum applied to practically all metals and ceramics, and finally sophisticated and economic applications in a number of industries.