Changsha lnstitute of Mining Research (CIMR) with rich design experiences is the earliest to be engaged in Research on downhole drilling tools and Rock drill bits in China and has carried on the work more than 25 years.

        Since 1972,J series hammers and various Rock drll bits have been developed, among them two products have won the prices of the National Science Conferences and fourteen products obtained scientific and technical achievement prices from the Metaillurgy ,Ministry. All the products have been widely used in metal,coal,and industrial mineral mines, hydroelectrie construction sites and sold to the foreign markets as well.

         CIMR Machinery plant is a department responsible for trial-producing, manufacturing and marketing the research achievements of CIMR,it has started manufacturing hammers and Rock drill bits since 1958.

        The second generation (Model B) of J series hammers recently produced by the plant possesses the charactrics of larger impact energy,higher penetration speed ;compared with insert bits,the Z type button bits have higher penetration rate and longer service life-With the backing of strong research force,its products are always of advanced structure and reliable quality.

        The plant can research,design and manufacture various new products and provide technical advice or service according to the customer requirements.