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ASTM B477 Gold-Nickel-Silver Electrical Contact Alloy

ASTM B477 Au-Ni-Ag is a precious metal alloy formulated for use in electrical contacts.

The properties of ASTM B477 Au-Ni-Ag include four common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare ASTM B477 Au-Ni-Ag to: precious metal electrical contact alloys (top), all alloys in the same category (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

95 GPa 14 x 106 psi

Elongation at Break

5.5 to 11 %

Knoop Hardness

100 to 190

Poisson's Ratio


Shear Modulus

34 GPa 4.9 x 106 psi

Shear Strength

190 to 320 MPa 27 to 46 x 103 psi

Tensile Strength: Ultimate (UTS)

310 to 550 MPa 45 to 80 x 103 psi

Thermal Properties

Latent Heat of Fusion

80 J/g

Melting Completion (Liquidus)

1010 °C 1850 °F

Melting Onset (Solidus)

930 °C 1700 °F

Specific Heat Capacity

160 J/kg-K 0.039 BTU/lb-°F

Thermal Expansion

15 µm/m-K

Other Material Properties


17 g/cm3 1060 lb/ft3

Electrical Conductivity: Equal Volume

14 % IACS

Electrical Conductivity: Equal Weight (Specific)

7.5 % IACS

Common Calculations

Stiffness to Weight: Axial

3.1 points

Stiffness to Weight: Bending

8.9 points

Strength to Weight: Axial

5.0 to 9.0 points

Strength to Weight: Bending

6.0 to 8.8 points

Thermal Shock Resistance

16 to 28 points

Alloy Composition

Gold (Au)Au 74.2 to 75.8
Silver (Ag)Ag 21.4 to 22.6
Nickel (Ni)Ni 2.6 to 3.4
Residualsres. 0 to 0.3

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM B477: Standard Specification for Gold-Silver-Nickel Electrical Contact Alloy

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015