We are offering outburst prevention drill. mainly used with efficient outburst prevention drill pipe, widely used in the coal mine coal lane, half coal rock drain, detection release, gas, pressure relief hole operation. Drill bit steel body selects the high quality steel, cutting head adopts imported brand coating alloy. Ensure the strength and hardness of drill bit. the main specifications are 44mm, 65mm, 76mm, 113mm, 150mm.