Abstract: Apparatus for producing annular corrugations in the wall of thin metal tubing in the manufacture of corrugated metal hose includes a plurality of dies. Each die comprises a helical rib of greater than 360.degree. extent formed on the inner rim of an annular ring with the ribs on successive dies being progressively thinner and having successively closer pitches so as to progressively deepen the corrugations and make them narrower. The dies are preferably mounted to rotate in synchronization with each other at identical angular speeds, and are arranged in pairs in one or more stages with the dies in each stage engaging opposite sides of the tube.