· Depth of nitration case:0.5—0.8mm
· Hardness of nitration:950—1020Hv
· Fragility of nitration:Less than grade 1
· Roughness of the surface：Ra 0.4μm
· Linearity of the screw:0.015mm
· The surface hard chromium plating hardness after nitration:≥950Hv
· Chromium-plating layer thickness:HRC55°—62°
· Hardness of double alloys:0.03—0.08mm
· Depth of double alloys:> 2mm