Metal Casting (Sand casting)

Metal Casting:

• Sand casting uses ordinary sand as the primary mould material. 

• The sand grains are mixed with small amounts of other materials, such as clay and water, to improve mouldability and cohesive strength, and are then packed around a pattern that has the shape of the desired casting.

• The pattern must be removed before pouring, the mold is usually made in two or more pieces.

• An opening called a sprue hole is cut from the top ofthe mold through the sand and connected to a system of channels called runners.

• The molten metal is poured into the sprue hole, flows through the runners, and enters the mold cavity through an opening called a gate.

• Gravity flow is the most common means of introducing the metal into the mold.

• After solidification, the mold is broken and the finished casting is removed.

• The casting is then “fettled” by cutting off the ingate and the feeder head.

• Because the mold is destroyed, a new mold must be made for each casting.