Quideline of technique

Depth of nitration layer: 0.05~0.08mm
Hardness of nitration: 900~1000hv
Fragility of nitration: less than grand one
Roughness of the surface: Ra0.4
Linearity of the screw: 0.015mm/m
The surface hardness of chrom plating after nitrogention:more than 950hv
Chrome-plating layer thickness:0.025~0.085mm