Abstract: A mold system for casting five-sided, monolithic, seamless concrete products comprises an outside jacket, an inside mold core complete with base, and a movable pallet to aid stripping. The outside jacket preferably includes two L-shaped panel members arranged in a rectangular configuration which are supported for movement between open and closed positions by a pair of base-mounted corner actuators extending from the fixed base to the apex of each panel member. The panel members are also linked to one another by a series of actuators along each of the adjoining two corners of the jacket. The inside core includes four interior panels linked by four inside retractable corners. A minimum of two series of actuators also span the middle portion of the inside core. These middle actuators in conjunction with the actuators in the corner devices function to expand and contract the entire inside mold core. A plurality of base supported actuators are fastened to the inside core.