Nickel, nickel-copper, and nickel-chromium-iron alloys were included in an atmospheric corrosion test series in industrial, marine, and rural sites. Pit depths, losses in weight, and losses in mechanical properties were extremely small after a seven-year period of exposure. The nickel-iron-chromium materials had the lowest corrosion rates, about 0.01 milligrams per square decimeter per day (about 0.002 mils per year). The corrosion rates of the nickel-iron-chromium alloys appear to have decreased substantially with exposure time, while the nickel and nickel-copper alloy specimens follow approximately linear rates. Long time durability data have also been obtained for a number of nickel-copper-iron alloys. These were boldly exposed at Bayonne, N. J., for almost 40 years. Data led to the construction of isograms connecting compositions of equal durability on the nickel-iron-copper ternary diagram. Effects of exposure under shelter are also discussed.