Top and bottom ferrous carrier plates have a plurality of pairs of mating window cavities. Pairs of mating nonferrous pre-molded inserts with mating mold cavities snap into mating window cavities with a rubberized retainer ring therebetween to create floating mating pre-molded insert molds in multiple material carrier plate assemblies. Liquefied material is dispensed through pot bushings and plungers in each top pre-molded insert. The liquefied material flows though gate openings located in each insert top surface filling the mold cavities. The liquefied material then solidifies to its permanent shape in the mold cavities.