... screw extruder 1.Suitable plastic material: PP,PE,,AS,PS etc. 2.Material: SACM-645, SCM440, 38CrMoALA 3.high qualtity twin screw extruderSize:screw ... diameter ø15-ø300mmMaximum screw length :10000mm 1.Hardness of adjuster:HB260 ... of the surface:Ra0.46.Linearity of the screw:0.015mm7.The surface hard chromium plating hardness ...