For the purpose of improving the spring properties of plain 60/40 brass, iron, aluminium, manganese, nickel, cadmium and tin were added to the alloy, and the alloys of Cu-Mn-Ni and Cu-Fe series were also examined. The conclusion obtained was as follows : (1) Among those elements, iron, manganese, aluminium, and tin were considered to be favorable to the purpose, and a satisfactory result might be obtained by increasing each content, unless injuring other practical processing. (2) The alloys of Cu-Mn-Ni series might be expected as the high heat-resistant spring material. (3) The alloys of Cu-Fe series also could be hopeful of spring materials, provided that those were suitably heat-treated during the manufacturing processes
