Now the mould is ready for the casting. The molten metal is poured in to the mold through the smaller front center hole which fills the mold from bottom back up to the top through the risers, which can be seen as 8 large holes. When the casting is cooling down the molten metal in the riser is drawn back down in to the casting. The risers act a main part in the casting process by supplying required molten metal during shrinkage.