FIELD: machine building.
SUBSTANCE: invention relates to the field of engineering, in particular to the treatment of metals by pressure, and can be used to process shaped tubes of square section. Method includes rolling the stiffeners directed at the inside of the pipe by rolling on at least two of its opposite sides of the pipe. In this case, the height of the ribs and the width of the rolled portion are selected, depending on the thickness of the pipe wall and the width of the pipe profile.
EFFECT: improves the quality of products by providing the specified profile along the entire length.
8 cl, 10 dwg, 1 tbl
