Alloy 42 Properties

alloy 42 properties physical mechanical expansion chemistry specificationsEFINEA is the unsurpassed leader in supplying controlled expansion, nickel-iron alloys to the industry. Below you will find pertinent material characteristics to aide in your evaluation of Alloy 42. Tables include average linear coefficient of thermal expansion, physical and mechanical properties, chemistry, and specifications for this alloy.


Our professional team of material experts are located on the east and west coast and ready to take your call. Contact us at 800-348-6268 for further information about the features of Alloy 42.


For an EFINEA Alloy 42 data sheet, or any other Controlled Expansion Alloy data sheets, please go to the Data Sheets section in our Technical Library.

Alloy 42 Average Linear Coefficient of Thermal Expansion µm/m • °C

Temperature Range °CUNS K94100Temperature Range °CUNS K94100
30 to 300 4.0 to 4.7*30 to 700 10.5
30 to 400 6.030 to 800 11.4
30 to 450 6.7 to 7.4*30 to 90012.3
30 to 500 7.930 to 100013.2
30 to 600 9.6
Source: ASTM F30, Table X1.1, UNS K94100; *tested range per ASTM F30, Table 2

To compare the linear coefficient of thermal expansion across our line of controlled expansion glass and sealing alloys, please refer to the Thermal Expansion Table.

Alloy 42 Typical Physical Properties

Densitylb/cu in0.293
Specific Gravity8.12
Curie Temp°F716
Melting Point°F2600
Electrical Resistivityohm-cir mil/ft430
Thermal ConductivityBTU-in/sq. ft-hr-°F74.5
W/cm °C0.11
Specific HeatBTU/lb °F0.12
Source: ASTM F30, 42 Alloy | UNS K94100; CarTech Glass Sealing 42 Data Sheet v. 7.1.90

Alloy 42 Typical Mechanical Properties

Tensile Strengthksi75
Yield Strengthksi40
Elongation% in 2 in.30
Hardness Ann.Rockwell B76
Modulus of Elasticity ksi21.5 x 103
Source: CarTech Glass Sealing 42 Data Sheet v. 7.1.90; Material in the annealed condition.

Alloy 42 Chemistry

Nickel, nominal41.00
Manganese, max. 0.80
Silicon, max. 0.30
Carbon, max. 0.05
Chromium, max. 0.25
Phosphorus, max. 0.025
Sulfur, max. 0.025
Cobalt, max.*
Aluminum, max. 0.10
*Cobalt is present as an incidental element and shall be reported separately.
Source: ASTM F30

Alloy 42 Specifications

ASTM F30MIL-I-23011 CL 5AMS 1-23011 CL 5UNS K94100

For additional information on specifications of the materials distributed by EFINEA, please visit the websites of the international organizations that develop and publish technical standards: ASTM International and ASM International.