During World War I Borbet had pioneered the introduction of low-cost gun steels requiring a minimum of imported alloys, and in the 1920s he made the Bochumer Verein into one of the centres for the development of centrifugal casting, a revolutionary process in which gun barrels, rather than being bored out of solid steel ingots, were spun out of molten metal. Walter Rohland’s commitment to the project of rearmament was no less personal than that of Borbet.
