The drill rods and subs are manufactured with high-quality steel to achieve a 30% increase in service life. They are processed by a high-precision NC lathe, ensuring no air leakage at the threaded connection. All threads have undergone special heat treatment to ensure high strength and abrasion. The drill rods and subs are connected using friction welding technology. Next, they are treated using medium-frequency induction heating technique to eliminate residual stress. Because of our unique processing method, we can guarantee drilling tools of superior quality.