CERTIFICATE FOR THE PROMOTION OF ROLLS BY CONTINUAL STRENGTH TESTING AND RECOVERY ORDER

摘要

A process and apparatus for the production of tube by continuous extrusion, in which material is fed to a passageway having a progressively decreasing cross-sectional area and defined by a first member rotatable relative to a second member, and a die ring co-operating with the first and second members to provide an annular extrusion path. The die ring may also be rotatable and be offset from the axis of rotation of the first member. The first member and die ring form a major part of said passageway, and the second member forms a minor part of the passageway, and the relative movement therebetween causes material fed to the passageway to be drawn along the passageway by frictional drag and to be extruded as tube through the annular extrusion path.