... base of series of rock drilling tools, mining tools, DTH Drill tools. Construction tools and excavating coal pick cutter tools, we can also produce other ... standard hex. Bit diameters include 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Shank H22x 108mm, (6, 7 ... , 38mm, etc.8. Blast furnace tap hole drill tools. (Rod, Cross bits, button bits and X-type bits etc). conical pick tools