DISC SEPARATOR The Disc Separator is designed for high performance, critical length sizing and the removal of oversized or undersized grain in one pass through the machine. As cereal grains pass through the machine, discs with indented pockets revolve through the material lifting that which fits into the pockets. Discs are available in solid or quick-change splits, grey iron or nickel plated, with a variety of pocket sizes to handle virtually any grain separation.