Abstract: To produce hollow profiles from sheet-metal blanks, the invention uses at least two process steps to form said blanks into a slit profile which is subsequently welded to produce the finished welded profile. For this purpose a mandrel is used which cooperates with a first tool part in the first step, and with a second tool part in the second step, such as to form a gap with the recess of each tool part into which a portion of the sheet-metal blank is guided. Shaping the sheet-metal blank in at least two steps means that a mandrel that is a self-contained component and can therefore be moved by a simple control device can be used to support the sheet-metal blank while the slit profile is being created. This considerably reduces the equipment needed to produce the hollow profile. Moreover, forming the sheet-metal blank into the slit profile in at least two steps also considerably improves the reliability with which this shaping takes place.

Abstract: A method for producing a longitudinally welded hollow profile from a sheet metal blank having defined longitudinal edges, in which the sheet metal blank is initially preformed into an open seam profile with the aid of at least two tool parts allows for the economical production of accurately formed hollow profiles. This is achieved in that to produce the open seam profile, the sheet metal blank, by a change in the relative position of the tools parts, is placed freely around a mandrel positioned between the tool parts and extending in the longitudinal direction of the sheet metal blank, the outer shape of which mandrel determines the inner shape of the hollow profile to be produced, and in that the shaping of the open seam profile obtained is then completed in one or more stages in each case by a further change of the relative position of the tool parts.

Abstract: A method for producing a longitudinally welded hollow profile from a sheet metal blank having defined longitudinal edges, in which the sheet metal blank is initially preformed into an open seam profile with the aid of at least two tool parts allows for the economical production of accurately formed hollow profiles. This is achieved in that to produce the open seam profile, the sheet metal blank, by a change in the relative position of the tools parts, is placed freely around a mandrel positioned between the tool parts and extending in the longitudinal direction of the sheet metal blank, the outer shape of which mandrel determines the inner shape of the hollow profile to be produced, and in that the shaping of the open seam profile obtained is then completed in one or more stages in each case by a further change of the relative position of the tool parts.