Patent ID: 8087277

Claim:
A method for correcting a metal tube having a side wall and first and second ends, the method comprising: preparing a press die, the press die further comprising: upper and lower dies having forming recesses including semi-oval cross-sectional profiles which form a forming space with a substantially oval cross-section that is wide in a die width direction when the dies are closed; a parting line between the upper and lower dies that is deviated from a position of a major axis of the forming space toward an upper die side by a predetermined height; an opening width of the forming recess of the lower die is set larger than an opening width of the upper die forming recess; walls disposed on at least one of the upper and lower dies that close both ends of the forming space, and wherein the upper and lower dies are curved in their lengthwise directions so as to form bent portions at intermediate parts of the upper and lower dies, closing the press die to compress the side wall of the metal tube with the upper and lower dies and to longitudinally restrain the first and seconds ends of the metal tube with the walls so as to plastically deform the metal tube such that the metal tube has a substantially oval cross-section.