Morning Session - Friday, June 24, 1932 - Manufacture of Seamless Pipe and Tubes

To explain in detail the manufacture of seamless pipe and tubes is something I venture to say that has never been done to a point entirely satisfactory. The manufacture of seamless tubes dates back to 1885, when Mannesmann Brothers invented the roll-piercing mill. Ten years later R. C. Stiefel invented the disc-piercer, which first came into general use in this country. At the present time the Mannesmann roll and the Stiefel disc-piercers are used, the Mannesmann rolls particularly for the larger size billets. Sizes produced at first were relatively small and the product was cold drawn to provide a smooth surface. The early uses of seamless material were chiefly for mechanical purposes, such as boiler tubes and bicycle tubing, and the latter for some years taking the heaviest tonnage. Improvements in the hot process were gradually made; the early Pilger type rolls were largely superseded by the two-high rolling mill for rolling out the tube after being pierced, the reeling machine for diagonal rolling, the sizing mill for giving exact outside diameter, and finally the sinking mill for reducing larger diameter tubes to smaller diameters.