Abstract: There is provided an electrolytic integrated polishing apparatus which enables high precision polishing of the internal surface of a long sized cylindrical workpiece such as a metallic tube. The apparatus includes a work supporting unit for disposing the cylindrical workpiece, so that the axial center of the cylindrical portion is aligned with the vertical direction, a rotation shaft supported downward along the vertical direction and free-rotatably supported in an external tube which is freely movable along the vertical direction, a tool electrode including a grindstone directed to radial directions, attached to the tip of the rotation shaft, and a plastic tube wound around the external surface of the external tube for pressurization.

Abstract: There is provided an electrolytic integrated polishing apparatus which enables high precision polishing of the internal surface of a long sized cylindrical workpiece such as a metallic tube. The apparatus includes a work supporting unit 13 for disposing the cylindrical workpiece W, so that the axial center of the cylindrical portion is aligned with the vertical direction, a rotation shaft 4 supported downward along the vertical direction and free-rotatably supported in an external tube 3 which is freely movable along the vertical direction, a tool electrode 5 including a grindstone directed to radial directions, attached to the tip of the rotation shaft 4, and a plastic tube 6 wound around the external surface of the external tube 3 for pressurization.

Abstract: A photoreceptor drum substrate comprising a drum of aluminum or aluminum alloy polished at the surface by centerless polishing. The photoreceptor drum substrate is manufactured by applying extrusion to a blank made of aluminum or aluminum alloy, then applying drawing to obtain a pipe material with less than 0.1% of bending to the entire length and satisfying the relation for wall thickness t, outer diameter .phi. and yield strength .sigma..sub.0.2, t.sup.2 .times..sigma..sub.0.2 /.phi..gtoreq.0.2 and then applying centerless polishing to the surface of the drum.

Abstract: An aluminum material suitable for forming the substrate of a photoconductor, such as a photoconductive drum, for electrophotographic copying machine, capable of being satisfactorily mirror-finished by precision machining. The Ti content of the aluminum material is less than 0.008% by weight. The aluminum material contains at least one of Mg, Si and Mn. The Mg content, Si content and Mn content of the aluminum material are in the range of 0.1 to 5.0% by weight, in the range of 0.1 to 1.0% by weight and in the range of 0.1 to 1.5% by weight, respectively.