Abstract: Disclosed is a tubular core on which sheets of metal or other material can be wound and supported, for shipment, handling and dispersal, and a method for forming the core. The core comprises a metal sheet or strip which has a rectangular-ribbed cross-sectional profile of flattened ribs, and which is wound spirally into a tubular configuration. The core is formed by passing the strip through a plurality of roll-forming stands, to initiate forming and progressively form an arcuate ribbed sinusoidal profile, then a final roll-forming pass is used (or several such passes are used) to flatten the ribs of the profile so that the rectangular flattened ribs collectively form a support surface for the sheets which are wound and supported on the core.

Abstract: A machine and method for making spiral pipe from a continuous strip of sheet metal including a corrugating mill which forms corrugations in the strip and drives it through a three-roll bending mill which bends the strip into helical convolutions and guides adjacent edges thereof into an interlocking relationship and a pair of lock up rolls for crimping the interlocked edges of the convolutions into a continuous seam, which rolls are manually or automatically adjustable radially relative to the pipe axis whereby its diameter may be accurately controlled. Adjustment of said rolls radially inwardly effects a diameter increase whereas adjustment outwardly decreases the diameter of the pipe.