1.PDC coal mining tools 2.ore mining, many type 3.good price,high quality 4. ... base of series of rock drilling tools, mining tools, DTH Drill tools. Construction tools and excavating coal pick cutter tools, we ... , standard hex. Bit diameters include 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Shank H22x 108mm, (6, ... bits, button bits and X-type bits etc). PDC coal mining tools