Abstract: A corrugated pipe forming apparatus and method in which flat sheet metal is passed through a plurality of first and second opposite roller pairs and deformed into a corrugated sheet. Lateral lips are formed parallel to the edges of the sheet and extend generally perpendicular to the sheet over the full length thereof. A pipe rolling machine helically deforms the corrugated sheet and folds the lip into a mechanical lock seam defining Pittsburgh lock of predetermined dimensions and tolerances. To maintain such dimensions and tolerances the width of the lips is adjusted by simultaneously moving one roll of each set in identical increments towards and away from the other roll of each set to thereby correspondingly change the depth of the corrugations and the width of the lips. The sheet can be moved laterally to maintain the lips of equal width. Corrugating stations of the device are defined by opposed corrugating rollers with the upper rollers held on a first frame and the lower rollers held on a second frame.