Depth of Nitrated Layer: 0.5-0.8mm             Hardness of nitration: 900-1020Hv
Fragility of nitration: Less than grade 1       Surface roughness: Ra 0.4um 
Hardness of Cr-coating Layer: ≥950Hv        Thickness of Cr-coated Layer: 0.03-0.08mm Hardness of Bimetallic Layer: HRC55-72       Depth of Bimetallic Layer: >2mm

We supply various types of screw barrel ,if you have any inquiry,do not hesitate to inform us.