REDUCING AND STRETCHING ROLLING MILL WITH IMPROVED TOLERANCE OF DIAMETER AND WALL THICKNESS Russian patent published in 2021 - IPC B21B17/14 B21B31/00 

FIELD: pipe production.

SUBSTANCE: invention relates to a reduction-stretching rolling mill for the manufacture of seamless pipes. The mill contains a set of rolling stands, which are arranged one after another in the direction of the pipe feed and each of which has three rolls located at an angular distance of 120°. The rolling stands are divided into at least two groups, each of which contains at least two rolling stands. The rolls of the neighboring rolling stands in the group are crossed relative to each other by an intra-group angle, and the rolls of the rolling stands of the neighboring groups are crossed relative to each other by a group angle that is less than the intra-group angle.

EFFECT: ensured uniformity of the rolled pipe wall thicknesses.

9 cl, 3 dwg