Difference Between SMC and BMC

SMC is a combination of long chopped glass strands, mineral fillers and liquid thermosetting resin in the form of a malleable sheet material. Processing of SMC of is typically done by compression or injection molding.
Sheet Molding Compound (SMC) is a compression molding compound often used for larger parts where higher mechanical strength is needed. SMC is a fiber reinforced thermoset material. Glass reinforcement is between 10% and 60%, and glass length is slightly longer than Bulk Molding Compound (BMC) - between 1/2-inch and 1-inch (25mm).

BMC is a combination of short chopped glass strands, mineral fillers and liquid thermosetting resin in the form of a bulk material. BMC is suitable for either compression or injection molding.
Bulk Molding Compound (BMC) is a thermoset plastic resin blend of various inert fillers, fiber reinforcement, catalysts, stabilizers, and pigments that form a viscous, 'puttylike' injection molding compound. Bulk Molding Compound (BMC) is highly filled and reinforced with short fibers. Glass reinforcement represents between 10% and 30%, with glass length typically between 1/32-inch and 1/2-inch (12.5mm).

Bulk Molding Compound (BMC) is a thermoset plastic resin blend of various inert fillers, fiber reinforcement, catalysts, stabilizers, and pigments that form a viscous, 'puttylike' injection molding compound. Bulk Molding Compound (BMC) is highly filled and reinforced with short fibers. Glass reinforcement represents between 10% and 30%, with glass length typically between 1/32-inch and 1/2-inch (12.5mm).