... high quality 3Processed to drawing or buyers request Alloy steel conical twin screw barrel for extruder machineSpecification:35/76, 45/90, 45 ... chrome coated layer 4Cr5MoSiV1,SKD-61,SKD-11Spraying bimetal alloy layer and nitriding treatment HPM38,SI36,SUS440,9Cr18MoV high ... of application : PVCwood-plastic., PE wood-plastic,,Super high polymer board,1/2 high Calcium buckle,50-400 high Calcium ...