Green sand

Green sand is a type of mold material used in metal casting, primarily made from a mixture of sand, clay, water, and other additives. It is called "green" because it is moist and unbaked when used, not because of its color. The mixture is packed around a pattern to create a mold, into which molten metal is poured. After casting, the mold is broken away to reveal the metal part. Green sand is popular due to its reusability, cost-effectiveness, and good dimensional accuracy for producing metal components in various sizes.