Abstract: The present disclosure relates to a size reduction apparatus such as a granulating machine of the type for cutting plastics and the like. The granulating machine includes a chamber provided with a driven rotor having a plurality of cutting elements mounted on the periphery thereof, each cutting element having in turn a plurality of spaced cutting knives. The cutting knives cooperate with stationary bed knives to comminute materials fed into the cutting chamber. The downstroke side of the cutting chamber is further provided with an access opening normally closed during cutting operations by a cover, which may be of particularly heavy slotted construction and which provides a backup surface for the material being comminuted. The disclosed granulating machine is particularly useful in comminuting large chunks of plastic material such as heavy purging, thick sheet and cast blocks. Machines of this type are designated as hog type granulators in the industry.