A mold is a cavity in a material that receives liquid metal and produces a cooled object in the shape of that cavity. Molds can be simple. The forms used to create ingots of metal are like loaf pans, with the metal simply poured inside and left to cool. Most molds are for more complex shapes and are based on a pattern. The pattern imprinted into a split mold. Half of the pattern is imprinted on one side of the mold and half on the other, and then the halves are clamped together before the mold is filled. http://www.kegao-precision.com/connector-mould-parts/