1.Diamond bits 2.coal mining,many types 3.good price ... steels (Integral Drill Rods)Shank H22x108mm, H19x108mm, standard hex, Bit diameters include 20-42mm.2. Tapered drilling tools (Tapered Drill ... ):Spherical, ballistic and Conical.(Threaded R32, T38, T45,T51, bit diameter: 45mm-127mm);Couplings sleeves-manufactured with a middle stop ... Cross type bits, button bits and X type bits etc) Diamond bits