... manufacturer specializes in producing kinds of rock drilling tools includes taper chisel bits, cross bits, button bits, tapered ... according to the different working conditions.The chisel drill rock tools are made from grade hard alloy and ... the rock hole within diameter of 50mm. The chisel rock drill tool is used in metallurgy mine, ... taper:4.8,6,7,11,12The diameter for taper:15,19,22,24,25(mm) Drill ...