C725 Copper-Nickel-Tin Alloy Wire (CuNi9Sn2)

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Alloy C725 is a moderate strength, low conductivity alloy with excellent bare solderability and corrosion resistance. Applications include electronic parts, springs, connectors and wire wrap terminals.

Mechanical Properties

Round Wire

Temper Name  Temper Code  Tensile Strength (ksi) Mill Limits 
Min Max
Annealed   55 65 .0010 - .1285 inch
1/4 Hard H01 65 80
1/2 Hard H02 75 90
3/4 Hard H03 80 95
Hard H04 95 110
Spring H08 110 125

Square Wire

Temper Name  Temper Code  Tensile Strength (ksi) Mill Limits 
Min Max
Annealed   55 65 .0100 - .0808 inch
1/4 Hard H01 65 80
1/2 Hard H02 75 90
3/4 Hard H03 80 95
Hard H04 95 110
Spring H08 110 125

Rolled Flat

Temper Name  Temper Code  Tensile Strength (ksi) Mill Limits 
Min Max
Annealed   45 65

Thickness:
.0100 - .0500 inch

Width:
.0150 - .2500 inch

1/4 Hard H01 55 75
1/2 Hard H02 65 80
Hard H04 75 90
Extra Hard H06 80 95
Spring H08 85 100

Physical Properties

Melting Point (Liquidis) 2065°F
Melting Point (Solidus) 1940°F
Density 0.321 lbs/cu in
Electrical Resistivity (Annealed) 94.3 ?(cir mil/ft) @ 68°F
Electrical Conductivity (Annealed) 11% IACS @ 68°F
Thermal Conductivity (Solutionized-Aged) 31 Btu ft/sq ft hr °F @ 68°F
Coefficient of Thermal Expansion 0.0000092°F (68-572°F)
Modulus of Elasticity (Tension) 20000 ksi
Modulus of Rigidity 7500 ksi