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Copper Alloy C90700 vs CuNi2SiCr

Copper Alloy · grade comparison

Copper Alloy C90700 and CuNi2SiCr are both copper alloy grades. CuNi2SiCr is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 152 MPa (22 ksi) for C90700, about 3.3 times as much; tensile strength follows at 600 MPa (87 ksi) vs 305 MPa (44.2 ksi). CuNi2SiCr is harder — 190 HB against 80 HB for C90700 — which matters for wear surfaces and threads. CuNi2SiCr is stiffer (132 GPa vs 110 GPa) and CuNi2SiCr runs hotter in service (350°C vs 250°C continuous). On the shop floor, CuNi2SiCr welds better (fair vs poor) and CuNi2SiCr forms better (fair vs not recommended).

CuNi2SiCrChoose it when strength drives the design, or when surface hardness matters.

C90700 vs CuNi2SiCr: properties

C90700CuNi2SiCr

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

110 GPa16 Msi
132 GPa19.1 Msi

Shear Modulus

41 GPa5.9 Msi
50 GPa7.3 Msi

Bulk Modulus

115 GPa16.7 Msi
138 GPa20 Msi

Tensile Strength (Ultimate)

305 MPa44.2 ksi
600 MPa87 ksi

Yield Strength (0.2% offset)

152 MPa22 ksi
500 MPa72.5 ksi

Reduction in Area

12%
30%

Compressive Strength

420 MPa60.9 ksi
520 MPa75.4 ksi

Shear Strength

205 MPa29.7 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

105 MPa15.2 ksi
230 MPa33.4 ksi

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

80 HB
190 HB

Hardness, Rockwell B

41 HRB
91 HRB

Hardness, Vickers

85 HV
200 HV

Same in both: Poisson's Ratio 0.34 · Elongation at Break 12%

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

830°C1,526 °F
1,050°C1,922 °F

Liquidus Temperature

1,000°C1,832 °F
1,090°C1,994 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 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)

18.4 µm/m·K10.2 µin/in·°F
17.6 µm/m·K9.8 µin/in·°F

Latent Heat of Fusion

170 J/g73.1 BTU/lb
205 J/g88.1 BTU/lb

Max Service Temperature (continuous)

250°C482 °F
350°C662 °F

Same in both: Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.9 % IACS
36 % IACS

Electrical Resistivity

1.58×10⁻⁷ Ω·m6.22 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)

-0.31 V
-0.25 V

Corrosion Resistance

65 / 100
60 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

60%
30%

Weldability

25 / 100
50 / 100

Formability (cold)

10 / 100
35 / 100

Castability

80 / 100
50 / 100

Brazeability / Solderability

85 / 100
70 / 100

Polishability

70 / 100
80 / 100

Same in both: Machinability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

45%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

35 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

12.5 MN·m/kg
15 MN·m/kg

Modulus of Resilience

105 kJ/m³
947 kJ/m³

Thermal Diffusivity

15.1 mm²/s
47.8 mm²/s

Thermal Shock Resistance Index

8
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 scaleCuNi2SiCrC90700

Manufacturing and finishing

CapabilityC90700CuNi2SiCr
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.

C90700 vs CuNi2SiCr — frequently asked

Is CuNi2SiCr stronger than C90700?

Yes. CuNi2SiCr has a typical yield strength of 500 MPa (72.5 ksi) against 152 MPa (22 ksi) for C90700 — about 3.3 times as much. Tensile strength is 600 MPa (87 ksi) vs 305 MPa (44.2 ksi).

Which is cheaper, C90700 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 welds better, C90700 or CuNi2SiCr?

CuNi2SiCr. Its weldability rates fair (50/100) against poor (25/100) for C90700.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C90700 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.