The invention relates to a method for producing hollow profile-members having a longitudinal flange, wherein a plate which is arranged between the stamp and the first die being preshaped by introducing a stamp into a first die to form an U-shaped profile-member having a first member and a second member, and wherein the U-shaped profile-member being shaped with a second die to form an O-shaped profile-member having a longitudinal flange. In one aspect, the plate is preshaped to form the U-shaped profile-member, a longitudinal flange member portion is shaped in at least the first member and the longitudinal flange member portion is constructed during the shaping of the U-shaped profile-member to form an O-shaped profile-member substantially in a shape-retaining manner to form a portion of the longitudinal flange.