CoMill is designed for size reduction application. Co Mill is designed for low heat, Low sound, low energy consumption operation and speed variation. Particles fall from the hopper into the blades of the mill which are moving at a very high RPM. The impact of the blades on the particles is the cause of the sizing is designed for size reduction application. Co-Mill is designed for low heat, Low sound, low energy consumption operation and speed variation. Particles fall from the hopper into the blades of the mill which are moving at a very high RPM. The impact of the blades on the particles is the cause of the sizing.