Design Nomenclature / Physical Model Making

Flash

Also called fin, flashing, spew

Material that squeezed into the gap between mould halves and cured there — a thin fin standing proud of the parting line. It reports clamping pressure lost to the pour or the injection, not a design error. Trimming it is quick; the ghost of the seam it leaves behind is what actually costs the afternoon.

Detail section at a mould split that has opened slightly under pressure. A thin blade of material has run out along the gap and stands perpendicular to the part's surface at the seam.

Not to be confused with

How this term connects

Body fillerGateGrit progressionMoldParting lineFlash
Related Confused with