... bits, Coupling, Shank Adaptors, DTH Bits and hammer. Shandong Sanshan Group Co., Ltd. ("SSG") was established in 2003. It consists of Shandong ... technology of rock drill steel and special steel by itself. The products are widely used in machinery, engineering construction, oil ... Wuyue Special and Rock Drill Steel Co., Ltd. Yanggu Sanshan Natural Co., Ltd. deals in the supply and trade of natural gas. ...