Continuous Cast vs. Centrifugal Cast

In continuous casting, molten metal enters a water-cooled graphite die and solidifies from the die wall inward while the strand is withdrawn at a controlled rate. Because conditions along the strand are constant, structure and dimensions are consistent along the whole length, and lengths are limited only by handling and cutting.

In centrifugal casting, a mould rotates about its axis — horizontally for long tubes, vertically for rings and shorter cylinders — while metal is poured in. Centrifugal force holds the metal against the mould wall and produces a sound outer surface, while lighter oxides and inclusions tend to collect at the inner diameter, where they are removed by boring.

Continuous casting is strongest for solid bar and modest hollow sections in the sizes carried as standard stock, and for non-round profiles such as square and rectangular sections. Its economics improve with long runs of one section.

Centrifugal casting is strongest where diameter grows. Large sleeves, cylinder liners, rings and long tubes are natural centrifugal parts, and the process can also produce bi-metallic components by pouring a second alloy against a first, which continuous casting cannot do.

Continuous-cast sections have a uniform, fine structure and are supplied as machining stock with a predictable allowance, so a machinist can plan cuts confidently.

Centrifugally cast tubes carry more allowance on the bore because the inner region is expected to be removed. Once bored, the remaining wall is typically dense and sound, which is exactly what a wear sleeve or liner requires.

If the part is a shaft, bushing, guide, gland or prismatic body within standard section sizes, continuous-cast stock is normally the shorter and cheaper route. If the part is a large-diameter sleeve, liner, ring or long tube — or needs two different alloys in one wall — centrifugal casting is the process built for it.