Mold tapering: The twin-belt casting machine differs from other moving mold casting machines in that all four mold surfaces are independent. This allows the mold surfaces to be tapered to remain in contact with the cast product as it shrinks. The high velocity cooling water, which is continuously applied to the backside of the belt, impinges on the belt and creates a force on the belt. This force acts to press the belt against the surface of the strip or slab as it shrinks, keeping the belt in close contact with the cast product throughout the mold. Each side of the mold is formed by an endless chain of dam blocks, which are held against the cast strip by adjustable spring-loaded guides.