In metallurgy , the process of shaping metal and increasing its strength by hammering or pressing.
In most forging an upper die is forced against a heated workpiece positioned on a stationary lower die. To increase the force of the blow, power is sometimes applied to augment gravity. The number of blows struck is carefully gauged by the operator to give maximum effect with minimum wear on the die. Forging presses employ hydraulic or mechanical pressure instead of blows; most can exert only a few hundred tons of pressure, but giant presses, used for forging parts of jet aircraft, are capable of up to 50,000 tons of pressure. See also drop forging .