The centrifugal casting process is typically used to cast cylindrical shaped castings. Centrifugal casting involves a cylindrical shaped mold. This mold is then rotated or spun about its axis at a predetermined speed. The castings wall thickness is controlled by the amount of material added during the pouring stage. Due to the nature of the centrifugal casting process the inner diameter of the part must always be round in shape. Most impurities in the metal generally have a lower density than the metal itself. During the casting process these impurities will collect in the inner diameter of the casting and can be removed during the casting process. This yields a casting with fewer impurities.