Sand Casting, is the oldest and most widely used casting process. It involves the pouring of molten metal into a sand mold and then breaking the mold after the part solidifies. Heat treatment is sometimes required depending on the desired grain structure. The sand mold is sacrificed every time a part is removed, hence a new mold is necessary to make another part. Also, nearly all alloys can be cast, including those with extremely high melting points. Production ranges from one to the millions, and part sizes range from very small to very large.