Common specifications: φ94, φ98, φ103, φ113, φ120, φ133, etc. Other specifications and special requirements can be customized according to specific requirements.

For the problem that after the gas drainage boreholes in soft and outburst coal seams are sealed, the boreholes are prone to collapse during the drainage process, resulting in premature abandonment of the boreholes and affecting the drainage effect. After the gas drainage boreholes are formed, the drill pipe is not withdrawn temporarily. The screen pipe is delivered to the bottom of the hole through the inner hole of the drill pipe, and then the drill pipe is withdrawn to leave the screen pipe in the hole.

This drill bit has a three - wing or four - wing structure. The central wing is flexibly hinged, which can realize the rapid lowering of the screen pipe and improve the drilling efficiency.