... Blower system Ring-die and rollers materials are alloy steel,Hardness more than 52 The new product FD series “double vertical ... are alloy steel,Heat treatment made by ourselves,Hardness more than 52,In this hardness can assure the pelleting quality and warranty ... pressure together,Produced more capacity,At the same time assure hardness and density,The special design is 4 rollers working,Increase ...