Abstract: A copper-nickel-silicon-chromium alloy having the combination of high hardness and high electrical conductivity. The alloy is composed by weight of 9.5% to 11.5% nickel, in an amount sufficient to provide a nickel-silicon ratio of 3.4 to 4.5, 0.5% to 2.0% chromium, and the balance copper. The alloy is heat treated by initially heating the alloy to a solution temperature and is thereafter quenched. The quenched alloy is then aged to precipitate the metal silicides. Because of the specific ratio of nickel to silicon, the heat treated alloy develops during heat treatment a hardness in excess of 30 Rockwell C and an electrical conductivity in excess of 24% of pure copper.