INCOLOY Alloy 903

Overview INCOLOY® alloy 903 (UNS N19903) is an agehardenable nickel-iron-cobalt alloy whose outstanding characteristics are a constant low coefficient of thermal expansion, a constant modulus of elasticity, and high strength. Application INCOLOY® alloy 903‘s characteristics make it an excellent candidate for applications such as rocket-engine thrust chambers, steam-turbine bolts, springs, gage blocks, and ordnance hardware Chemical Composition (%) Nickel Cobalt Aluminum Titanium Niobium Iron 36.0 to 40.0 13.0 to 17.0 0.3 to 1.15 1.0 to 1.85 2.4 to 3.5 Balance* Reference to the ‘balance’ of an alloy’s composition does not guarantee this is exclusively of the element mentioned, but that it predominates and others are present only in minimal quantities. Physical Properties Density Melting Points Specific Heat Tensile Modulus 8.25 g/cm3(RT)   1318-1393°C 442J/kg .°C（50°C） 146.9GPa (50°C） Our alloy 903 bar, pipe, plate, round rod, wire, tube constant low coefficient of thermal expansion, which makes it an excellent candidate for applications such as rocket-engine thrust chambers, steam-turbine bolts, springs, gage blocks, and ordnance hardware.