extruder screw and barrel

extruder screw and barrel 1.Technics: 1):Heat-treatment 2):Nitriding-treatment 3):Spray alloy coating 4):Hard-chrome electroplated 2.Technical parameter: 1):Depth of Nitration Layer:0.5-0.8mm 2):Hardness of Nitration:900-1000HV 3):Fragility of Nitration:Less than grade 1 4):Roughness of the surface:Ra0.4 5):Straightness of the screw:0.015mm 6):Surface hardness of Nitrated Cr coating Layer:>=950Hv 7):The thickness of Chrome-plating layer:0.025-0.085mm 8):Depth of alloy Layer:>2mm