... material: bimetallic layer PP,PE,PVC,PET,ABS,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel Zhejiang Bohai Conical twin screw ... /77,45/90,51/10,55/110,65/120,65/132,70/140,75/150,80/156, 80/172,90/184 ... Depth1.5mm-3.5mmWarranty period:2-4years(Depends on the plastic raw materials)Bimetallic: much longer lifetime.Nitriding timeOver 180 hours ...