China United Mould

Deflashing, Machining & Finishing

Secondary operations

Deflashing and finishing after molding

Every thermoset part comes out of the mold with a thin flash along the parting line or shear edge, so deflashing is the first operation. After that the part gets whatever it needs before assembly: drilled holes, machined faces, inserts, bonding, painting or labels.

Cured BMC and SMC are abrasive and cannot be remelted or welded, so machining uses carbide or PCD tools with dust extraction, and painting needs a primer suited to the compound.

Deflashing a compression molded SMC part with a file
CMM inspection of a molded thermoset part

Operations

Secondary operations FAQ

How is flash removed from SMC and BMC parts?

By trimming and filing along the parting line and shear edge, or by media blasting or tumbling for smaller BMC parts.

Can SMC and BMC parts be machined?

Yes, with carbide or PCD tools and dust extraction, because the glass fibers are abrasive. Drilling and trimming are the most common operations.

Have a BMC or SMC part in mind? Send us your drawing for a quotation.