Conical Twin Screw and Barrel/Cylinder for PVC/WPC extrusion. Size: 45/90, 51/105, 65/132, 80/156, 92/188 Base Raw Material for screw :38CrMoAlA, A grade, Special alloy is welded on the screw arris, prolong life of the screwBase Raw Material for barrel: 38CrMoAlA, A grade, easy wearing parts of barrel made from anti-wear alloy, can be improved abrasion performance.Nitriding treatment, surface ...