Features > Hammer Mills > Size Reduction EquipmentFEATURES. Motor drive directly coupled to rotor assembly. V-belt drive optional. Large, obstruction-free product feed opening. Convenient access door for rapid.characteristics of hammer mill,Hammer Mill Operating Principle - 911 MetallurgistFeb 25, 2016 . Operational Characteristics: The method of operation has a . When minimum fines are a requirement, the hammer mill should always he.