氮化层深度：0.5-0.8mm       Depth of nitration case : 0.5-0.8mm

氮化硬度：950-1020HV        Hardness of nitration: 950-1020HV

氮化脆度：≤一级            Fragility of nitration: Less than grade 1

表面粗糙度：Ra0.4um         Roughness of the surface: Ra 0.4un

螺杆直线度：0.015mm         Lineatity of the screw: 0.015mm

双合金硬度：HRC55-62        Hardness of double alloys :HRC55-62

双合金深度：》2mm           Depth of double alloys:》2mm