According to the operating process of the Raise borer Machine, during the drilling of the guide hole, the drill rod is responsible for transmitting the downward thrust and torque generated by the main engine to the roller bit, enabling it to crush the rock through compaction; during the reaming process, the drill rod is responsible for transmitting the upward pulling force and torque generated by the main engine to the reaming cutter head, allowing the rolling cutters on the cutter head to crush the rock wall through compaction.

Due to the working characteristics of the Raise borer Machine, the drill rod is responsible for transmitting large axial forces and torques throughout the operation process, which places high demands on the material of the drill rod and the form of the connecting threads. As shown in the table below:

× —— Not applicable

✔ —— Applicable (connecting thread is one inch four teeth)

þ—— Applicable (connecting thread is one inch two teeth)

Note:^*1—— Applicable when the reaming depth does not exceed 100m.

Among them, the one inch four teeth and one inch two teeth thread specifications are both suitable for the working conditions of the drill rod. Relatively speaking, the one inch four teeth thread drill rod is simpler and lower in cost to process, but the helical rise angle of the threaded part is relatively small, and the tooth shape is relatively small, so the torque that can be transmitted without damaging the base of the threaded part is relatively small; while the processing difficulty and cost of the one inch two teeth thread are relatively high, but due to its larger helical rise angle and larger tooth shape, the torque that can be transmitted without breaking the base of the threaded part is relatively large. Therefore, when matching drill rods, the one inch two teeth thread drill rod of the same specification has a wider applicable hole diameter.