Nickel, in substantially pure form, is widely used in industry for its corrosion resistance combined with moderate mechanical strength and good thermal and electrical conductivity. The principal high nickel alloy contains approximately 99.5 percent nickel and small amounts of manganese, magnesium, and carbon. A wide variety of nickel alloys with widely differing properties are commercially available. These have been listed in six categories: nickel alloys such as nickel 200; nickel-copper alloys such as Monel alloy R-500; nickel-chromium alloys such as Nimonic alloy 75; nickel-molybdenum alloys such as Hastelloy B; nickel-iron-chromium alloys such as Incoloy alloy 800; and high temperature-high strength alloys such as Astroloy.