drawing of tubes is cold, comprising a reduction in thickness in several stages in the course of a same passes

摘要

P drawing of tubes, having a thickness reduction in several steps during a single pass. / p & & p & the invention proposes a head of the mandrel comprising a first cylindrical section is traditionally joined angularly to a second working section of smaller diameter, and disposed inside the opening of the bushing in a fixed position, with the first section is traditionally adjacent to the exit side of the opening of the die, and the seal of the section being disposed inside the attenuation zone, so that the completion of the reduction of the internal surface of the tube machine when that - latter is pulled axially is carried out at the interior of the attenuation zone. Applicable to the drawing of tubes in general. / p