... Φ44mm-Φ175mm.It is divided into two wings combined and multi-level drill bit. And could be used with variety of highly ... ,Enterprise is introduced and the enterprise culture,Linqing City Ruilong Drill CO.,LTD,Was established in 1993.Located in China's ... specializing in the production of mine, drilling and supporting the drill pipe.Operation Ideas:Management principle:Talents-oriented,practice and high ...