Alloy 48 Properties

alloy 48 properties physical mechanical expansion chemistry specificationsEFINEA understands that the mechanical and physical properties of Alloy 48 are key factors in the evaluation of this material for selection for any given application. As a general reference for assessing this alloy the data below contains typical Alloy 48 properties. Included in the tables are the mechanical and physical properties, average linear coefficient of thermal expansion (CTE), as well as the chemistry and specifications for this low expansion alloy.


EFINEA is a leading supplier of iron-nickel alloys for electronic applications. Our teams are trained in the special purpose alloys we distribute including our on-staff metallurgical expertise.


Navigate to the Technical Literature section within the Technical Library of our website for an extensive fifty-year archive of scholarly papers on the materials we supply. Also,  contained in our Technical Library you can download a copy of the EFINEA Alloy 48 data sheet or any or our other Controlled Expansion data sheets, by following the link to the Data Sheets section in our Technical Library.

Alloy 48 Average Linear Coefficient of Thermal Expansion µm/m • °C

Temperature Range °CUNS K94800Temperature Range °CUNS K94800
30 to 300 8.830 to 700 11.3
30 to 400*8.2 to 9.2*30 to 800 12.1
30 to 500 9.430 to 900 13.0
30 to 550*9.6 to 10.3*30 to 100013.9
30 to 600 10.4
Source: ASTM F30-96 (2017), Table X1.1, 48 Alloy; *ASTM F30-96 Table 2 Range

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 48 Typical Physical Properties

Densitylb/cu in0.298
Specific Gravity8.25
Curie Temp°F880
Melting Point°F2640
Electrical Resistivity*ohm-cir mil/ft - (68° F)283
microhms-cm -( 20° C)47
Thermal Conductivity*BTU-in/sq. ft-hr- °F
(68° F)
W/m °C (20° C)16.7
Source: ASTM F30-96 (2017) | *Special Metals Corp. Nilo 48 Data v. 9/04

Alloy 48 Typical Mechanical Properties

Tensile Strengthksi75
Yield Strengthksi38
Elongation% in 2 in.43
Hardness Ann.Rockwell HRB max.80
Modulus of Elasticity ksi23.2
Hot-rolled, annealed bar
Source: Special Metals Corp. Nilo 48 Data v.9/04

Alloy 48 Chemistry

Nickel, nominal48.0
Manganese, max0.80
Silicon, max0.30
Carbon, max0.05
Chromium, max0.25
Cobalt, max*
Phosphorus, max0.025
Sulfur, max0.025
Aluminum, max0.10
The nickel contents listed are nominal. The nickel contents of the alloys shall be adjusted by the manufacturer so that the alloys meet the requirements for thermal expansion.
Cobalt is present as an incidental element and shall be reported separately.
Source: ASTM F30

Alloy 48 Specifications

ASTM F30MIL-1-23011 CL 3AMS 1-23011 CL 3UNS K94800

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.