Steel extrusion screw

Screw diameter:Ø15-Ø300 Aspect ratio:15-46 Product type: For different plastic products screw can be used: ordinary type, pin type, barrier type, separation type, exhaust type and so on. Base material: 1)38CrMoAlA(JIS SACM645) 2)42CrMo(AISI 4140) Process: Heat treatment Nitriding treatment Technical Parameters: Nitriding depth: 0.50mm-0.80mm Nitriding hardness: 900-1000HV Nitriding: <= Level 1 Surface roughness: Ra 0.4 Screw straightness: 0.015mm The hardness of the surface after chrome plating:≥950HV Chromium layer thickness: 0.025~0.085mm Double alloy depth: 3mm