The material costs for the process are low and the sand casting process is exceptionally flexible. A number of metals can be used for castings in sizes from ounces to many thousand pounds. The mold material is reclaimable, with between 90 and 95% of the sand being recycled, although new sand and additions are required to make up for the discarded loss. These features, combined with the relative ease of mold production, have ensured that the green sand molding process has remained as the principal method by which castings are produced