Titanium Grade 21s

UNS R58210


Aircraft Engine Components and Ductwork


Titanium Grade 21s is a metastable beta titanium alloy that offers substantial strength to weight ratios. It offers the high strength of metastable beta titanium alloys along with improved oxidation resistance, elevated temperature strength, and creep resistance. TI21s is a good choice for metal matrix compositions because it can be rolled to a foil, is compatible with most fibers, and is thermally stable to 816°C. Grade 21s is known to be extremely resistant aircraft hydraulic fluid, making it perfect for the aerospace industry.

Industries Supplied


Nominal Composition

C: 0.05 max
O: 0.11 - 0.17
N: 0.050 max
H: 0.02 max
Mo: 14.0 - 16.0
Nb: 2.4 - 3.2 
Al: 2.5 - 3.5 
Si: 0.15 - 0.25 
Fe: 0.400 max
Ti: Balance
Res. Each: 0.10 max
Res. Total: 0.40 max 

Physical Properties

Density: 0.178 lb/in3, (4.93 g/cm3)

Modulus of Elasticity (E): 
At 70°F (20°C): 15.2 x 103 ksi (105 GPa)

Modulus of Rigidity (G)
At 70°F (20°C):  5.7 x 103 ksi (39.5 GPa)

Coefficient of Expansion:
3.93 µin/in.-°F (70°F to 1000°F)
7.07 µm/m-°C (20°C to 538°C)

Electrical Resistivity: 53 µΩ.in, (1.35 µΩ.cm)

Thermal Conductivity: 4.4 Btu-in./ft.hr.-°F, (4.93 W/m-K)

Applicable Specifications

Strip and Foil: ASTM B 265

Typical Mechanical Properties

  • Annealed
    • Heat Treatment: Proprietary Continuous Furnace Anneal
    • Tensile Strength: 115-140 ksi (793-965 MPa) 
    • Suggested Operating Conditions: 0-°F to 1100°F (-18°C to 538°C)
  • Annealed and Aged
  • Heat Treatment: 1000°F (538°C) for 8 hours
  • Tensile Strength: 170 ksi min (1172 MPa min)
  • Suggested Operating Conditions: 0-°F to 1100°F (-18°C to 538°C)

  • For further information Contact:

    Email: stripinfo@elgiloy.com
    Phone: 1 888 843 2350 
    Elgiloy Specialty Metals - Strip Products
    1565 Fleetwood Dr.
    Elgin, IL 60123 USA