Bulk Molding Compound (BMC) or bulk moulding composite is a ready to mold glass-fiber reinforced thermoset polymer material primarily used in compression molding, as well as in injection molding and transfer molding. Typical applications include electrical, automotive, transportation, and corrosion resistant needs.

BMC is manufactured by mixing strands of chopped glass fibers, styrene, an initiator and fiber in a mixer with an unsaturated thermoset resin (commonly polyester resin, vinyl ester resin or epoxy resin ). The mixing is done at room temperature and stored at low temperatures to slow down curing prior to molding. The glass fibers in BMC increase the strength properties of the products to be higher than the standard thermoplastic products