Patent ID: 8281629

Claim:
A method of producing a ring member comprising: a cutting process in which a rectangular sheet material is formed by cutting a strip-shaped material pulled out from a coiled material; a joining process in which opposite edges of the sheet material are butted, and a cylindrical member is formed by joining the edges to each other; and a ring formation process in which a ring member with a ring shape is formed by cutting the cylindrical member in a direction perpendicular to an axis of the cylindrical member, wherein, in the cutting process, i) the strip-shaped material is cut along one of a first section line parallel to a reference section line that is an edge of the strip-shaped material facing a direction in which the strip-shaped material is pulled, or a second section line perpendicular to the reference section line, and then ii) the strip-shaped material is cut along the other of the first section line or the second section line, that is perpendicular to the line previously cut, and wherein the cutting process is performed before the joining process.