with 8 gundrill machines,short manufacturing time pellet mill roller: 1,alloy steel; 2,for 420 pellet mill 3,life time:200 tons pellets 4 ... ,best selling420pellet mill roller:420 pellet mill roller is the rollerused in MZLH 420 biomass fuel pellet mill ... alloy steel is most suitable for making biomass fuel pellets. ring die