SPECTRUM Solid Body Pin Drive Master Bushing is conforming to API-7K specification suitable for 27-½" .The advantage of using Pin Drive Master Bushings makes it possible to use extended split bowls in the rotary table while the Kelly bushing is in operation.

Extended bowls provide better slip back ups & this back up is made to be used for running in heavier tubular strings without string failure due to bottle necking. Master Bushing with appropriate insert bowl in use can hold maximum of 500 tons string load. These Master Bushings are provided with locks to secure the bowls into the bushings.