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ASTM B780 Silver-Copper-Nickel Electrical Contact Alloy

ASTM B780 alloy is a precious metal alloy formulated for use in electrical contacts.

The properties of ASTM B780 alloy include six 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 B780 alloy 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

83 GPa 12 x 106 psi

Elongation at Break

1.1 to 9.1 %

Poisson's Ratio


Shear Modulus

30 GPa 4.4 x 106 psi

Shear Strength

200 to 340 MPa 28 to 49 x 103 psi

Tensile Strength: Ultimate (UTS)

330 to 590 MPa 48 to 86 x 103 psi

Thermal Properties

Latent Heat of Fusion

140 J/g

Specific Heat Capacity

270 J/kg-K 0.065 BTU/lb-°F

Thermal Expansion

18 µm/m-K

Other Material Properties


10 g/cm3 630 lb/ft3

Electrical Conductivity: Equal Volume

70 to 76 % IACS

Electrical Conductivity: Equal Weight (Specific)

62 to 68 % IACS

Common Calculations

Stiffness to Weight: Axial

4.5 points

Stiffness to Weight: Bending

14 points

Strength to Weight: Axial

9.1 to 16 points

Strength to Weight: Bending

11 to 15 points

Thermal Shock Resistance

16 to 29 points

Alloy Composition

Silver (Ag)Ag 74 to 76
Copper (Cu)Cu 23.5 to 25.7
Nickel (Ni)Ni 0.35 to 0.65
Zinc (Zn)Zn 0 to 0.060
Iron (Fe)Fe 0 to 0.050
Cadmium (Cd)Cd 0 to 0.050
Lead (Pb)Pb 0 to 0.030

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

Followup Questions

Similar Alloys

Further Reading

ASTM B780: Standard Specification for 75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact Alloy