Extruder Barrel and Screw Specification : Ø15mm~Ø500mm 
Draw Ratio： L/D=7~55 
 
Technical Parameter
Quenching and Tempering Hardness：HB280-320
Screw Straightness：0.015mm
Nitriding Hardness：HV850-1000
Nitrided Chromium Coating Surface Hardness≥900HV
Nitriding Depth ：0.45~0.7mm
Chromium Coating Thickness ：0.025~0.10mm
Nitridng Brittleness :2 Level
Duplex Alloy Hardness：HRC50-65
Surface Roughness：≤Ra0.4
Duplex Alloy Depth：0.8~2.0mm
Materials and Technologies
Quality 38CrMoAIA (41CrAIMo7)
SKD61(H13)
Quality Duplex Stainless Steel
Gr12MoV
42CrMo
Quality Powder Metallurgy Materials
40Cr
Hard Metal Cold/Thermal Spraying Technology
Zinc 3# Steel
Advanced Nitriding Technology
Anti-corrosion and Wear-resisting Duplex Metal Spraying Technology
 
 
https://www.gmscrews.com/single-screw-extruder-screw-and-barrel/