Prebreakers are "multi-pass" grinders where materials enter one end an exit the opposite end after having been conveyed during the grinding process. These are Heavy Duty machines designed to handle large particle reduction. They are available in 6, 10,12,15 and 24" diameters with volumes ranging from 1,000 to 60,000 pounds per hour capacity.

"Comb" style Grinders are "single pass" grinders the product enters the top of the machine and exits out the bottom of the machine. As a result product sizing is largely a function of the width of the "teeth" of the comb. This style grinder offers the benefit of using less horsepower and is more tolerant of foreign materials (often called tramp) due to low shaft RPM.