Below is a list of Forgings manufacturers from Diamond Bar, California. Forgings are metal parts produced through a forming process in which the metal is given a particular shape through the application of a compressing force. The pressure causes plastic deformation of the metal and alters the grain flow to follow the shape of the part. This gives the part a more dense structure and increases its directional strength. Although the metal is often preheated prior to the forging process, it is never melted or poured as in the die casting process.