... 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, ... . All kinds of casing bits for shield machine and construction tools.7. Round road planning bit for road milling machine ...