... a professional manufacture of rock drilling tools, mining tools, DTH Drilling tools. construction tools and excavating coal pick cutter tools ... steels(Integral Drill Rods)Shank H22x108mm, H19x108mm,standard hex, Bit diameters include 20-42mm.2.Tapered drilling tools(Tapered ... , ballistic and Conical.(Threaded R32, T38, T45,T51, bit diametre:45mm-127mm);Couplings sleeves-manufactured with a middle stop ...