Metal forging is a process of hammering and pressing the metal, exerting high localized pressures, to form the shape out of the blank and it is chosen when you require the part to have better structural characteristics than a similar machined or casted part. Forging can be quite a versatile process as it can used to produce from a few parts to over millions of parts in a wide variety of materials. Forged parts are usually post processed by machining, heat treatments etc to achieve desired dimensions and properties.