The roll crusher is designed for a gradual size reduction in one, two, or three stages, depending upon the ratio of feed size to desired finished product size. With proper selection of roll speed and differential, roll separating force, roll clearance, and number and type of corrugations, the roll crusher may be arranged to granulate, grind, pulverize, crack, crumble, or fracture an unlimited number of materials, chemicals, minerals, and plastics.