TUBE PRODUCTION METHOD Russian patent published in 1994 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of deforming a tube blank by forced rotation of it around its lengthwise axis in a round pass, formed by rolls in a mandrel; providing deformation on a portion of the deformation zone with a reduction value of the wall, equal to a value of an admittance range for the wall thickness (the above mentioned portion is arranged at an outlet side), with parameter relation, determined according to a mathematic expression, given in description of the invention. EFFECT: enhanced efficiency. 1 cl, 1 tbl