Centrifugal casting (industrial)

In centrifugal casting, a permanent mold is rotated continuously at high speeds (300 to 3000 rpm) as the molten metal is poured.

It is notably used to cast cylinder liners and sleeve valves for piston engines, parts which could not be reliably manufactured otherwise.

Typical products made using this process are television tubes and missile nose cones.

[citation needed] Spin casting is also used to manufacture large telescope mirrors, where the natural curve followed by the molten glass greatly reduces the amount of grinding required.

Rather than pouring glass into a mold an entire turntable containing the peripheral mold and the back pattern (a honeycomb pattern to reduce the mass of the finished product) is contained within a furnace and charged with the glass material used.

The assembly is then heated and spun at slow speed until the glass is liquid, then gradually cooled over a period of months.

Centrifugal casting is also used to manufacture disk and cylinder shaped objects such as railway carriage wheels or machine fittings where grain, flow, and balance are important to the durability and utility of the finished product.