What is forging?

   Forging is the shaping of metal, usually iron or steel, by heat and pressure. However, aluminum and other metals are also forged. In forging, the metal is never melted. It is heated until it becomes plastic, and then it is molded into shape by impact and pressure. The principal kinds of forging are: swaging, or the reducing of a larger piece to a smaller one; upsetting, or the enlargement of a smaller piece; bending; welding, or the uniting of one piece of metal to another; punching, or the formation of holes; and cutting off. Originally, all of these operations were performed by the blacksmith with hammer and anvil. However, with the development of modern industry and the tremendous increase in the quantity and size of operations, special equipment became necessary. Giant steam hammers have been constructed with a falling weight of from 2,000 to 5,000 pounds. These hammers form part of the equipment of drop forges. There are also forging presses that exert a pressure as high as 10 to 15 tons per square inch. For modern forging operations there are special dies that determine the required shape. For durability, these dies may be made of special alloys, such as vanadium steel.