A hollow profile having at least one laterally protruding flange and a method for the production thereof. The hollow profile having a hollow profile blank and a sheet metal strip. The hollow profile blank and the sheet metal strip each having a joining element and being adapted to be joined in a locking relationship. Wherein a hydraulic internal high pressure is generated within the hollow-profile blank and the joining element of the hollow-profile blank is shaped, whereby a non-releasable clamping action is formed between the joining elements of the hollow profile blank and the sheet metal strip.