For discharging gas, water exploration, grouting and blasting in tunnels. Hole size: 65-90mm, ... 25 and MKQJ 120/40 coal mine underground DTH drill rig features light in weight, easily transported, strong torque ... suitable to drill holes for discharging gas, water exploration, grouting and blasting in tunnels, and widely used in mining, ... DHD hammer and bit)375kg590kg Underground Anchor Hole Drill Rig