1.drill pipe 2.Taper:6,7,11,12. 3.ISO9001 ... tools and excavating coal pick cutter tools.1. Integral drill steels (Integral Drill Rods)Shank H22x108mm, H19x108mm, standard hex, Bit ... 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Drill rods with Shank H22x108mm,(6,7,11,12 ... ,etc.8. Blast furnace tap hole drill tools.(Rod, Cross type bits, button bits and X type bits etc) drill pipe