UNS #N19903

CTX-1 is a high-strength, precipitation-hardenable superalloy with high hot hardness and good thermal fatigue resistance, exhibiting a low coefficient of thermal expansion with high strength at temperatures up to 1200°F (649°C), requiring a protective coating if exposed to atmospheric conditions above 1000°F (538°C). It develops its stress rupture ductility through retained hot-cold work, resulting in directionality of properties. Although it continues to provide the highest strength levels of the controlled expansion high temperature alloys, later generation alloys, such as CTX-3, should be considered for applications involving elevated temperature transverse stress conditions and Thermo-Span® alloy should be considered if moderate oxidation resistance is desired.

Type Analysis

  • Carbon (Maximum) 0.05
  • Phosphorus (Maximum) 0.015
  • Silicon (Maximum) 0.5
  • Nickel (Nominal) 38.00-40.00
  • Titanium (Nominal) 1.25-1.75
  • Manganese (Maximum) 0.5
  • Sulfur (Maximum) 0.015
  • Chromium (Nominal) 0.5
  • Cobalt (Nominal) 14.00-16.00
  • Molybdenum (Nominal) 0.2
  • Iron (Nominal) Balance
  • Aluminum (Nominal) 0.70-1.20
  • Copper (Nominal) 0.5
  • Columbium + Tantalum2.50-3.50
  • Boron (Nominal) 0.008


Casings, seals, and other gas turbine engine components;extrusion dies, punches and mandrels; Ordnance hardware, Steam turbine blades, Gauge blocks, Springs, Rocket thrust chambers, Die casting dies

Applicable Specifications





Technical Information


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