... : 4.8, 6, 7, 11, 12 3.Water Hole: 2 Rock Drill Bits We are a manufacturer specializes in producing kinds of ... material according to the different working conditions. The quarry taper rock drill tools are made from grade hard alloy and special steel ... , generally matched with the light-duty rock drill, to drill the rock hole within diameter of 50mm. The drill tools are used in metallurgy mine ...