KELLY BAR IS THE KEY ELEMENT OF THE ROTARY DRILLING RIG THAT TRANSFERS THE TORQUE AND THE PULL-DOWN FROM THE RIG TO THE DRILLING TOOL. THE KELLY BAR COMPRISES OF HIGH STRENGTH BUT DUCTILE TELESCOPING STEEL TUBES WITH SPECIAL GUIDE STRIPS, DRIVE STRIPS, PULL-DOWN KEYS AND LOCKING ELEMENTS WELDED ONTO THE STEEL TUBES.