Delta Metal

Delta Metal is an alloy consisting of copper and zinc—in other words, brass—to which some manganese has been added in the form of ferro-manganese, or spiegel-eisen which contains manganese. A little silicon is also used, but enough of this is usually present in ferro-manganese. The iron added by the use of these substances should be kept small in quantity. Delta metal has similar properties to phosphor-bronze, if, indeed, some of it is not simply manganese-bronze. The silicon and the manganese modify the properties of copper in the same way as phosphorus does in the case of phosphor-bronze (see BRONZE). Delta metal is used for parts of machinery and for ornamental work. See the patents of G. A. Dick, the inventor of delta metal, No. 5914, December 1883, and No. 6172, April 1884.