Specification: Screw Diameter: D15- D 300 L/D ratio: 15-46 Product classification: Aiming at different plastic products the screw can be chosen from: General type, pin type, barrier type, separation type, and gas-exhausting type, etc. Base Materials: (1)38CrMoAlA(JIS SACM645) (2)42CrMo(AISI 4140) (3)4Cr5MoSi V1 (JIS SKD-61) (4)9Cr18MOV (5)HPT Bimetallic alloy materials: 1)Fe-based alloy 2)Ni-based alloy/Deloro alloy 3)Co-based alloy 4)NiCo-based alloy 5)Tungsten carbide/Wolfram carbide Technics: Heat treatment High-frequency quenching Nitriding treatment Hard-chrome electroplating Bimetallic alloy welding Bimetallic alloy centrifugal casting Technical parameter: Nitrided layer depth: 0.5-0.8mm Nitrided hardness: 900-1000HV Nitrided brittleness: less than grade 1 Surface roughness: Ra0.4 Linearity of screw: 0.015mm Hard-chrome plating hardness after nitriding: >950HV Chrome-plating layer depth: 0.025-0.085mm Bimetallic layer depth: 3mm Slushing Oil Coated& Film Wrapped in Wooden Case