The lower part of drum is made of chrome plated brass and is detachable so that different mesh screens (Sieves) coarse, Medium or fine supplied with the equipment can be easily placed. With hammers fixed to a disc of dia 1.5" thick through which passes a shaft being revolved at 3000 RPM. The hammers are enclosed in a drum, the sides and Supper surface of which are roughened. The inner surface is undulant.