... BS970 709M40,34CrNiMo6,BS970 826M40 We Shanghai ZENT Industrial Co., Ltd was established in 2006, situates in the Yangtze ... machining, and heat treatment. Shanghai ZENT Industrial Co., Ltd specializes in the free forging of carbon steel, alloy steel, stainless steel ... , China Special Alloy Shanghai ZENT Industrial Co.,LtdRoom 2302,No.729. Pujian Road . Pudong .Shanghai ,China forging retaining rings