... countries We are a professional productions base of series of rock drilling tools, mining tools, DTH Drill tools. Construction tools and ... steels(Integral Drill Rods)We are a professional manufacture of rock drilling tools, mining tools, DTH Drilling tools. construction tools and ... degree taper) taper rods in most lengths.button bits, cross type bits and chisel bits with(6,7,11,12 degree taper).Bit ...