Invar® Properties

Invar properties physical mechanical expansion chemistry specificationsEd Fagan Inc. is the unsurpassed leader in supplying nickel-iron alloys to the industry.  Below find Invar® properties tables which include the alloy’s physical and mechanical properties, its chemistry, the applicable specifications and comprehensive thermal expansion data.

Our experienced team of technical experts are available to answer your questions.  Please contact us at 800-348-6268 should you have any questions about our alloys.

For an Invar® alloy data sheet, or any other Controlled Expansion Alloy data sheets, please go to our Alloys and Metals Literature Library section.

Linear Coefficient of Thermal Expansion Invar 

Temperature Range °CExpansion Range 
30 to 1000.8-1.6per AMS I 23011 Cl 7
30 to 1501.2-2.7per ASTM F 1684
30 to 2001.3-2.1per AMS I 23011 Cl 7
30 to 3004.92nominal
30 to 3506.2-7.0per AMS I 23011 Cl 7
30 to 4007.8nominal
30 to 4508.5-9.2per AMS I 23011 Cl 7

For comparison linear coefficient of thermal expansion data on all of our controlled expansion, glass and ceramic sealing alloys, please refer to our Thermal Expansion Table.

Invar Physical Properties
Densitylb/cu in0.291
Specific Gravity8.05
Curie Temp°F535
Melting Point°F2600
Electrical ResistivityMicro-ohm-cm84
ohm-cir mil/ft495
Thermal ConductivityW/cm °C0.10
BTU-in/sq. ft-hr-72.6
Specific HeatCal/gm °C0.12
BTU/lbm- °F0.12
Thermal Expansionppm / °F (75°F to 842°F)4.9
ppm / °C (25°C to 450°C)8.9
Invar Mechanical Properties
Tensile Strengthksi75
Yield Strengthksi40
Elongation% in 2 in.34
Typical Hardness Ann.Rockwell HRB80
Modulus of ElasticityMpsi20.5
Invar Chemistry 
maximum % unless noted
Nominal Nickel35
Nominal Cobalt0.5
Invar Specifications
ASTM F1684MIL-1-23011 CL 7AMS 1-23011 CL 7UNS K93603 (Plate, Sheet)UNS K93050 (Free Cut)

For additional information on specifications of the materials distributed by Ed Fagan Inc., please visit the websites of the international standards organizations that develops and publishes technical standards, ASTM International and ASM International.