... : SACM-645, SCM440, 38CrMoALA 3.high qualtity single screw extruderSize:screw diameter ø15-ø300mmMaximum screw length :10000mm 1.Hardness of adjuster:HB260-2902 ... 15.Rougness of the surface:Ra0.46.Linearity of the screw:0.015mm7.The surface hard chromium plating hardness after nitrogenation ... ,PA,PC,ABS,AS etcWe can manufacture various kinds of screw barrels