Abstract: In injection molding, a mold forms a wall member, which defines a cavity, by bringing together two mold halves. The cavity wall is formed by a specially machined cavity plate having built-in support columns, fins and ejector pins columns. The plate forms a passageway and in-out flow chambers on the opposite side from the cavity surface which completely surrounds the cavity where coolant or heating circulating carrier flows at high rates. The resulting flow of coolant/heating carrier at high rates can be controlled by special positioning of the flow chambers and creates added turbulence. The built-in support columns, fins and ejector pins also dramatically increase the area of contact of the flow carrier with the cavity plate. The design incorporates built-in support columns and fins which make possible a thinner cavity surface plate by adding strength and structural support to the cavity area.