1 Hardness After Hardending&Tempering : HB240~280

2 Nitrided Hardness : HV900~950

3 Nitrided Case Depth : 0.55~0.7mm

4 Nitrided Brittleness :Less Than Grade 1

5 Surface Roughness :Ra 0.4

6 Surface Chromium-Plating’s Hardness After  Nitriding≥900HB

7 Screw Straightness 0.015mm

8 Chromium –plating Depth :0.05~0.10mm

9 Alloy hardness HRC 56-65

10 Alloy Depth 0.8~ 0.2mm

screw and barrel for extruder machine ,twin screw