rétreint à la molette

OBS: rétreint à la molette : terme obtenu d'un spécialiste du domaine.

CONT: ... a process now known in the [beverage can making] industry as ""spin flow necking."" ... a process where an externally located free spinning forming roll ... is moved inward and axially against the outside wall ... of the open end ... of a rotating trimmed can ... to form a conical neck at the open end ... a spring-loaded holder or slide roll ... supports the interior wall of the can ... and moves axially under the forming force of the free roll ... This is a single operation where the can rotates and the free roll ... rotates so that a smooth conical neck end is produced.
OBS: The essential difference between spin flow necking and other types of spin necking [is] the axial movement of both the external roll ... and the internal support.