Directly behind the mold disk is the crucible, which contains molten type metal at an optimal 535°. At the moment before casting, the mold disk moves forward on its slide. Studs in the mold disc engage with blocks on the vise so that the mold disc seats gently, yet tightly and squarely against the line of matrices held in the first elevator jaws and between the vise jaws. The vise jaws compress the line of matrices so molten metal is prevented from squeezing between the mats on cast. The crucible tilts forward, forcing the mouthpiece tightly against the back of the mold. The plunger in the well of the crucible quickly descends, forcing the molten metal up the crucible throat and injecting it into the mold cavity through the array of orifices in the mouthpiece. The jets of molten metal first contact against the casting face of the matrices, and then fills the mold cavity to provide a solid slug body. These have character shapes punched into them, so the result is a cast "slug" with the character shapes of the line on its top face. The mold disk is sometimes water-cooled, and often air-cooled with a blower, to carry away the heat of the molten type metal and allow the cast slugs to solidify quickly.