Description
| Nitriding layer depth: 0.5-0.7mm | The hardness of surface layer: HV960-1100 |
| Bimetal screw: Hardness of alloy layer HRC>60 | Alloy layer depth：1.22-2.03mm |
| Screw straightness：0.015mm | Chromium layer thickness：0.03-0.06mm |
| Surface finish：0.04Ra/um-0.08Ra/um | L/D ratio：（30-38）：1 |