It is applied to fine crushing of various material of which compressive strength is less than or equal to 320Mpa, is applied to relatively small feeding material granularity and relatively small discharging gate, and is fitted for the secondary crushing. BTMA provides a complete line of stone production; the output is widely used in road, bridge, house, high building, railway, highway, water project as the type of construction material, such as aggregate, foundation stone, etc.