twin conical screws barrels screw barrel,bimetallic screw barrel,extruder screw barrel,twinconical screw barrel,twin conical counter rotating screws barrels,twin screws barrels,plastic machinery parts,plastic machinery components Depth of Nitration Layer: 0.5-0.8mm Hardness of Nitration: 950-1020Hv Fragility of Nitration: Less than grade 1 Surface Roughness: Ra 0.4 um Streightness of Screw: 0.015mm Surface Hardness of Nitrated Cr coating Layer: >=950Hv The Thickness of Cr Coating Layer: .03-0.08mm Hardness of Alloy Plating: HRC55-620 Depth of Alloys Layer: >2.5mm -4mm Introduction: Used for producing PA, EVOH, EAA, PC etc. We can supplyall types of screws and barrels according to clients' requirements.