Centrifugal castings are created when hot metal is poured into a rotating mould. This is a great way to create cylindrical components as the rotating mould is great at creating uniform circular shapes. Centrifugal castings can differ greatly in size and will depend on the type of mould being used. Some castings can be as big as 10 feet in diameter and 50 feet in length. There is also another method that is used to create the same shapes at lower speeds - this is called semi-centrifugal casting.
When an item is rotated at high speed, centrifugal force is created. As the mould is spun the hot metal inside is thrown against the inner wall of the mould and this is how cylinders are created. Centrifugal casting is an efficient means of producing a wide range of components used in the automotive and engineering trades today.
Centrifugal castings can be used with metal, plaster, concrete and different types of resin. In fact, many special effects studios use a casting technique when they need to create prosthetic limbs and other parts. It all starts with a castings mould. This is used to create the exact shape desired. The material to be used - in this case resin or plaster - is poured into the mould and then the mould is broken open to reveal the finished product.
Silversmithing is a centrifugal castings method on a smaller scale. Use to create items of jewellery. this is a technique used by silversmiths the world over. The process involves minute amounts of molten silver to be poured into a small mould where it is spun on a rotating arm. Other products made using the centrifugal castings method include telescopic mirrors. The manufacturing process involves molten glass being poured into a mould. This is then spun and the mirror is spread evenly. Marbles are also made using the same centrifugal castings method.
Industrial centrifugal castings methods are used to create larger scale items such as fly wheels, pipes and large boilers. The premise is the same as any other casting method - molten metal is poured into the mould and the mould is rotated. Moulds can be rotated from 300 to 3000 rotations per minute depending on the desired result and the material being used. The metal is thrown against the side of the mould and any impurities end up on the inside of the product itself. You can often see impurities if you look inside a pipe or another metal cylinder.