Welding is the most common way of permanently joining metal parts. In this process, heat is applied to metal pieces which melts and fuses them to form a permanent bond. Because of its strength, welding is used in shipbuilding, automobile manufacturing and repair, aerospace and thousands of other manufacturing activities. Welding also is used to join steel beams in the construction of buildings, bridges and other structures, and to join pipes in pipelines, power plants and refineries.
