We couldn't have cars, buildings or even space rockets without welding techniques. In fact, about half of the U.S. gross national product involves welding [source: Hobart]. Welding is a technique that joins together two metal objects. Other techniques, such as soldering, brazing and riveting, can join metal objects, but use another material to do so. Welding is more efficient and versatile, and it produces a stronger product than other methods because it joins together the original pieces, so that the finished work is as strong as the original materials.
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