Our patented TwinDriveTM threads have been developed for rotary-percussive casings and inner rods to handle the increased percussive power of hydraulic drifters. A typical cylindrical or conical thread form has a concentration of the clamping stresses at the base of the male thread. The TwinDriveTM thread form distributes the clamping load of the rod joint along the full length of the thread resulting in lower stresses at any given point in the thread. This means that it takes much less torque to make and break the rod joint and provides up to 40% additional tooling life in hard ground conditions.
