... .Taper: 4.8, 6, 7, 11, 12 3.Water Hole: 2 Rock Drill Bits We are a manufacturer specializes in producing kinds ... taper chisel bits, cross bits, button bits, tapered drill rods, integral drill steels, plug hole integral steels, pick rods, thread cross bits, thread ... matched with the light-duty rock drill, to drill the rock hole within diameter of 50mm. The drill tools are used in metallurgy mine ...