FIELD: metallurgy.
SUBSTANCE: invention relates to metal forming and is used in the production tubing in the manufacture of pipes for very precise internal diameter. Mandrel has an operating part and positioned behind it in the form of a gauge portion of the cylindrical portion.
EFFECT: decrease in intensity of non-contact deformation of the pipe during the dispensing provided by the fact that the mandrel has a guide portion of the elastic member, and the working portion of the mandrel has a parabolic shape which blends in with the half-angle conical surface α vertex = 1÷3°.