PURPOSE: To offer a planetary reeler for improving the shape of inside surface and accuracy of thickness of tube which is rolled with a rolling mill of mandrel mill.

CONSTITUTION: The planetary reeler A is arranged on the downstream side of the rolling mill of mandrel mill, an inner cylinder 2 which is freely rotatably mounted inside an outer cylinder 1 is revolved through a driving source, spur gear 8 and external gear 5. While two rolls 3 of which the axial lines are inclined by a prescribed angle 10 the directions that are mutually contrary with respect to the moving direction of a tube which is inserted into the inlet side of the planetary reeler A and freely rotatably mounted to the inner cylinder 2 are revolved around the periphery of the tube, they are made to rotate on their own axes through internal gears 7 and planet gears 6. In such a way, the outer surface of the tube is reduced with the rolls 3.