Abstract: To provide an electrolytic integrated polishing method for the external surface of metallic tubes, wherein both dimensional precision such as roundness or the like and product yield can be improved, and aluminum alloy photosensitive drum substrates prepared thereby. A metallic tube, both ends of which are supported, is positively charged and rapidly rotated about the axis thereof. More than one grindstone are pressed with a constant pressure against the external surface of the metallic tube from opposite directions or radial directions having the rotation axis as the center of rotation. Negative pole electrodes are disposed so as to sandwich the grindstones along a circular direction to perform electrolytic integrated polishing by supplying electrolyte to the external surface of the metallic tube.

Abstract: A disclosure is made of a subterranean connecting method and a connecting apparatus therefor which are suitable for use when two shield machines are used to excavate a pair of tunnel sections from both ends of a tunnel, and the tunnel sections are connected to each other in mid course. During underground connection, it is important to secure sealing and water retarding with respect to soil and water pressure exerted by the ground in the vicinity of the connecting section. For this purpose, in the connecting apparatus, a penetration ring is arranged in one of the shield machines, and a penetration chamber in which the penetration ring is accommodated is arranged in the other shield machine. Both the both shield machines face each other with a slight gap remaining therebetween and, subsequently, the penetration ring is moved forward and penetrates into the penetration chamber of the mating shield machine. By this penetration, the area between both the shield machines are closed by the penetration ring.