Conical twin screw &barrel 1,Hardness After Hardending&Tempering : HB240~280 Technical Specification1,Hardness After Hardending&Tempering : HB240~2802,Nitrided Hardness : HV900~9503,Nitrided Case ... nitriding Process6,Corrosion & Abrasion Resistance Bimetal Spraying Process7,Horniness screw (HTP1:abrasion HTP2:corrosion resistance,HTP3:abrasion and corrosion resistance Conical twin screw &barrel