Forging is the process of forming and shaping metals through the use of hammering, pressing, or rolling. The process begins with starting stock, usually a cast ingot (or a "cogged" billet which has been already forged from a cast ingot), which is heated to its deformation temperature, then upset or "kneaded" between dies to the desired shape and size.

During the hot process, the cast, coarse grain structure is broken up and replaced by finer grains. Low-density areas, micro shrinkage and gas porosity inherent in the cast metal are consolidated through the reduction of the ingot, achieving sound centers and structural integrity. Mechanical properties are therefore improved through elimination of the cast structure, enhanced density, and improved homogeneity. Forging also provides means for aligning the grain flow to best obtain desired directional strengths. Secondary processing, such as heat-treating, can also be used to further refine the part. No other metalworking process can equal forging in its ability to develop the optimum combination of properties.