Patent ID: 8573260

Claim:
A metal pipe of single piece construction comprising: a wall formed of a single corrugated metal sheet, the sheet having opposing first and second edges extending longitudinally along the sheet, the wall including a seam formed by abutting portions of the first and second edges, the seam extending helically about and along a length of the wall, the metal sheet having an interior wall side and an opposing exterior wall side, the interior wall side defining an inner wall surface of the wall, the exterior wall side defining an outer wall surface of the wall, the sheet having a sinusoidal cross-sectional profile defining only 5 corrugation peaks at the inner wall surface and only 5 corrugation peaks at the outer wall surface, each corrugation peak residing between two adjacent sloped sections, the sheet having a flattened sheet width of approximately 27¼ inches and a finished sheet width of approximately 23 inches.