Zhoushan Changjia Plastic machinery Co.,Ltd. Conical Twin Screw Barrels Tempering hardness：HB260-290 Nitridation hardness：HV800-1050 Nitration case depth：0.4-0.7mm Nitridation brittleness ≤ grade 1 Surface roughness：Ra0.4 Screw straightness：0.015mm Chromium coating hardness after nitridation：≥900HV Chromium coating thickness：0.05-0.10mm Dual alloy hardness：HRC56-65 Dual alloy depth：0.8-2.0mm Barrel feed Section Material: High-quality steel ①38CrMoALA (JIS SACM645) ②316 stainless steel ③SKD61 Heat treatment: Nitriding treatment Hard chrome plating layer High-frequency quenching Spray corrosion resistance, wear-resistant bimetallic layer Vacuum hardening Contact us Add: No.1 Xitun Road, Xitun Industrial Zone, Jintang Town,Dinghai District, Zhoushan, Zhejiang, China Tel: +86 15957056012 Fax: +86 0576-85131178 Email: [email protected] Website: https://www.cjscrewbarrel.com