B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21B—ROLLING OF METAL
B21B23/00—Tube-rolling not restricted to methods provided for in only one of groups B21B17/00, B21B19/00, B21B21/00, e.g. combined processes planetary tube rolling, auxiliary arrangements, e.g. lubricating, special tube blanks, continuous casting combined with tube rolling
Partie active de mandrin, procede de laminage de pieces creuses longues dans un laminoir continu multicage a l'aide de ladite partie active, et pieces traitees conformement audit procede