N19903 Nickel Iron Cobalt Superalloy

The following data is provided for informational purposes only. It was provided with permission by Special Metals at www.specialmetals.com 

Incoloy®  903, also known as UNS N09903, is used known for having high strength, a constant low coefficient of thermal expansion, and a constant modulus of elasticity. Because of these characteristics, there is a always a need for parts forged in Incoloy®  903 in many industrial sectors.

Chemical Composition
(%max., unless shown as range or min.)

Ni Co Nb Ti Al Fe
Min./Max. 36.0-40.0 13.0-17.0 2.40-3.50 1.00-1.85 0.30-1.15 *Balance

*Reference to the ‘balance’ of a composition does not guarantee this is exclusively of the element mentioned but that it predominates and others are present only in minimal quantities.

Applicable Specifications 

Incoloy® 903 is designated UNS N19903. The alloy is available as sheet, plate, rode, bar and forging stock.

Common Fabrication Processes
Incoloy® 903  is a highly durable be forged into nearly any shape. This includes:

  • Rocket-Engine Thrust Chambers
  • Gage Blocks
  • Steam-Turbines Bolts,
  • Ordnance Hardware
  • Rings and Castings
  • Fasteners

Industries that Commonly use Incoloy® 903 Forgings:

  • Aerospace and Aviation Engineering
  • Power Generatio