This is what a wheel mold looks like. Essentially, a mold consists of several machined sections of steel that come together to create a cavity for molten aluminum to fill. American Eagle uses what is referred to as "counter-pressure casting technology." The way it works is like this: the negative cavity of the mold is pressurized with molten aluminum. The pressure causes the aluminum to flow into all sections of the mold, filling in any voids in the process. Because the process uses gravity at first to fill the mold, the mold is positioned vertically with the lower portion of the mold face-up. This lower section will create the front face of the wheel. The segmented side portions of the mold are known as side cores. There are typically six side cores for a given mold. The upper mold portion can be seen in the background of this photo, and the upper mold section creates the mounting or backside of the wheel face.