METHOD OF DRAWING TUBES ON CONE MANDREL Russian patent published in 1994 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of deforming a tubular blank by its diameter and thickness of its wall in a drawing die on a secured mandrel, having grooves on its cone working surface; determining width values of the grooves according two mathematical relations, given in description of the invention. EFFECT: enhanced quality of tube inner surface. 1 cl, 1 dwg