Conical twin screw &barrel 1,Surface Roughness :Ra 0.4 2,Screw Straightness :0.015mm Technical Specification1,Hardness ... 10mm9,Alloy Hardness : HRC55~6210,Alloy Depth :1.5~2.0mmMaterial&Processes1,Quality 38CrMoALA2,GH3#Steel3,Quality Powder ... Process7,Horniness screw (HTP1:abrasion HTP2:corrosion resistance,HTP3:abrasion and corrosion resistance) Conical twin screw &barrel for plastic extruder