Between all size reduction equipment, hammer mills are more widely used than any other to grind minerals and fodder. Now thanks to some special features of the mills series RP, they can be used in foodstuffs and chemicals industries too. Of simple, yet robust design, the hammer mills are suitable to meet the most medium size reduction requirements. They can be used to mill various materials: fibrous, tough, hard, crystalline, fragile, moist, fat and heat sensitive. Thanks to a series of adjustments (tip speed of the hammers, perforation sizes of the classifying screen, number and shape of the hammers themselves) it is possible to optimize the performance from the machine in relationship with the product to be treated. Since the inner temperature of the mill increases during running, which causes the product softening (for rubbers, elastomers and resins) or the leak of oily substances, it is possible to carry out cryogenic grinding.