Invar Alloy Properties

(Also know as Invar 36, NILO 36, Pernifer 36, and Invar Steel)

Invar Alloy Physical Properties

Density lb/cu in 0.291
Specific Gravity   8.05
Curie Temp °F 535
  °C 279
Melting Point °F 2600
  °C 1427
Electrical Resistivity Micro-ohm-cm 84
  Micro-ohm-cm 495
Thermal Conductivity W/cm °C 0.10
  BTU-in/sq. ft-hr- 72.6
Specific Heat Cal/g- °C 0.123
  BTU/lbm- °F 0.123
Thermal Expansion ppm/°F (75°F to 842°F) 4.9
  ppm/°C (25°C to 450°F) 8.9


Invar Alloy Mechanical Properties

Tensile Strength ksi 75
  MPa 518
Yield Strength ksi 40
  MPa 276
Elongation % in 2 in. 34
Typical Hardness Ann. Rockwell HRB 80
Modulus of Elasticity Mpsi 20.5
  kMPa 141


Invar Alloy Chemistry
maximum % unless noted

Iron Bal
Nominal Nickel 36
Nominal Cobalt 0.5
Carbon 0.05
Silicon 0.40
Sulfur 0.015
Chromium 0.25


Invar Alloy Linear Coefficient of Thermal Expansion

Degree C   Degree C
30-100 0.8 - 1.6 30-450 8.5 - 9.2
30-150 -- 30-475 --
30-200 1.3 - 2.1 30-500 9.7
30-250 -- 30-525 --
30-300 4.92 30-550 --
30-325 -- 30-600 11.4
30-350 6.2 - 7.0 30-700 12.7
30-375 -- 30-800 13.5
30-400 7.8 30-900 13.9
30-425 -- 30-1000 --