Below is a list of Green Sand Casting manufacturers from Grand Rapids, Michigan. Green sand casting uses disposable molds made of special sand based slurries to produce cast iron parts and components for a number of industrial uses. While some variations may actually appear green in color, the term is actually derived from wood working and references the wet state of the slurry during mold making. The quality of the final product depends largely on the quality of the slurry with consideration for parameters such as ability to hold shape, permeability, thermal strength, collapsibility and re-usability.