Pin Drive Roller Kelly Bushing
The Pin Drive Roller Kelly Bushing provides the following advantages:
1. Pulling out or feeding off string can be done while rotating;
2. Because of its integral construction, it can not fly out and hurts you;
3. The bushing is easily installed into the master bushing, maintaining good alignment;
The contact between Kelly and roller is rolling contact, so friction is lower, and weight on bit is accurate.
Pin Drive Roller Kelly Bushings