The granularity of stone enters sand making machine though belt conveyor. Stones will be crushed by hitting other stones. Material falls down to impellor cavity. Under the high speed centrifugal force, it hits material that coming downwards. After hitting each other, they force a vortex between impellor and shell, and hit each other several times, finally the smaller stone comes out from the bottom, and goes to vibrating screen. The qualified materials will be transported to sand washing machine, however unqualified materials will return to sand making machine to be crushed again. Output sizes can be made according to customer's requirement. If input size is larger than the designed size, other crushing equipment will be necessary.