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Copper Alloy C71500 vs CuNi2SiCr

Copper Alloy · grade comparison

Copper Alloy C71500 and CuNi2SiCr are both copper alloy grades. CuNi2SiCr is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 140 MPa (20.3 ksi) for C71500, about 3.6 times as much; tensile strength follows at 600 MPa (87 ksi) vs 380 MPa (55.1 ksi). In exchange, C71500 is the more ductile: elongation 45% versus 12% for CuNi2SiCr, and CuNi2SiCr is harder (190 HB vs 80 HB). C71500 is stiffer (152 GPa vs 132 GPa) and CuNi2SiCr conducts heat better (160 W/m·K vs 29 W/m·K). On the shop floor, CuNi2SiCr machines more easily (fair vs poor) and C71500 welds better (excellent vs fair).

C71500Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

CuNi2SiCrChoose it when strength drives the design, or when the part is machined in volume.

C71500 vs CuNi2SiCr: properties

C71500CuNi2SiCr

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

152 GPa22 Msi
132 GPa19.1 Msi

Shear Modulus

57 GPa8.3 Msi
50 GPa7.3 Msi

Bulk Modulus

158 GPa22.9 Msi
138 GPa20 Msi

Tensile Strength (Ultimate)

380 MPa55.1 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

140 MPa20.3 ksi
500 MPa72.5 ksi

Elongation at Break

45%
12%

Reduction in Area

55%
30%

Shear Strength

275 MPa39.9 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

140 MPa20.3 ksi
230 MPa33.4 ksi

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

80 HB
190 HB

Hardness, Rockwell B

45 HRB
91 HRB

Hardness, Vickers

85 HV
200 HV

Compressive Strength

—
520 MPa75.4 ksi

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

8.94 g/cm³0.32 lb/in³
8.8 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,171°C2,140 °F
1,050°C1,922 °F

Liquidus Temperature

1,238°C2,260 °F
1,090°C1,994 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

29 W/m·K16.8 BTU/hr·ft·°F
160 W/m·K92.4 BTU/hr·ft·°F

Specific Heat Capacity

377 J/kg·K0.09 BTU/lb·°F
380 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16.2 µm/m·K9 µin/in·°F
17.6 µm/m·K9.8 µin/in·°F

Latent Heat of Fusion

230 J/g98.9 BTU/lb
205 J/g88.1 BTU/lb

Same in both: Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

4.6 % IACS
36 % IACS

Electrical Resistivity

3.75×10⁻⁷ Ω·m14.8 µΩ·in
4.8×10⁻⁸ Ω·m1.89 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.25 V

Corrosion Resistance

82 / 100
60 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

30 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
30%

Weldability

85 / 100
50 / 100

Formability (cold)

90 / 100
35 / 100

Castability

45 / 100
50 / 100

Brazeability / Solderability

80 / 100
70 / 100

Same in both: Polishability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

7 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

43 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

17 MN·m/kg
15 MN·m/kg

Modulus of Resilience

64 kJ/m³
947 kJ/m³

Thermal Diffusivity

8.6 mm²/s
47.8 mm²/s

Thermal Shock Resistance Index

4
41

Strength versus weight

Yield strength against density for every copper alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

501002005001,0007.588.599.5Density (g/cm³)Yield strength (MPa) — log scaleCuNi2SiCrC71500

Manufacturing and finishing

CapabilityC71500CuNi2SiCr
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.

C71500 vs CuNi2SiCr — frequently asked

Is CuNi2SiCr stronger than C71500?

Yes. CuNi2SiCr has a typical yield strength of 500 MPa (72.5 ksi) against 140 MPa (20.3 ksi) for C71500 — about 3.6 times as much. Tensile strength is 600 MPa (87 ksi) vs 380 MPa (55.1 ksi).

Which is cheaper, C71500 or CuNi2SiCr?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, C71500 or CuNi2SiCr?

CuNi2SiCr. Its machinability rates fair (45/100) against poor (30/100) for C71500; for welding the order is C71500 first (excellent, 85/100) then CuNi2SiCr (fair, 50/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C71500 and CuNi2SiCr side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.