A power tong having a ring gear and dumbell rollers, with mating load surfaces on the ring gear and dumbell rollers which transfer horizontal and vertical loads from the ring gear to the dumbell rollers, without contact between the ring gear teeth and the dumbell rollers. The power tong further has a dumbell roller shaft configuration which permits vertical and rotational locking of the shaft, while permitting easy replacement and without binding of the rotation of the top and bottom plates on the dumbell rollers.