Material:
Alloy-steel of high-quality
1)38 CrMoAIA(JIS SACM645)
2)42CrMo(AISI4140)
3)9Cr18MOV
4)CW6Mo5Cr4V2
5)SKD61
Heat-treatment
Nitriding treatment
Electroplate hard-chrome
High-frequency quenching
Spraying corrosion wear-resisting dual metal layers
Vacuum quenching
Technical Parameter
Steel Material: DIN 41CrA1Mo7 / AST M4140 / GB 38CrMoAlA
Deepness of Nitriding Layer: 0.7 mm -0.9 mm
Hardness of Nitriding: HV900 - HV1, 000
Nitriding Brittleness: ≤ Grade 1
Chromate plating: Thickness 0.05 mm - 0.10 mm, hardness HV950
Special treatment: Carbide coating on screw flight and bimetallic barrel
Screw straight tolerance: 0.015 mm/m
Surface roughness: Ra 0.4μm