Diameter：Φ15-Φ300L/D Ratio：L/D=15-46Surface Roughness：Ra 0.4μmNitriding Layer Depth: 0.5～0.8mmNitriding Fragility：Less than Grade OneNitriding Layer Hardness: 900～1000HVCr-Plating Layer Depth: 0.05~0.10mmCr-Plating Layer Hardness: HV＞850Bimetallic Layer Depth: 1.2~2.5mmBimetallic Layer Hadness: HRC＞65Types of screws: ordinary type, gradient type, mutant type, barrier type, pin type, DIS open bar Merry, exhaust type, BM, separate type. Compression ratio, the number of screw head and the type of barrel can be designed according to users’ requirements.
