... 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, ... , 25mm, 30mm, 33mm, 38mm, etc.8. Blast furnace tap hole drill tools. (Rod, Cross bits, button bits and X-type bits etc ...