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Copper Alloy C26000 vs C66900

Copper Alloy · grade comparison

Copper Alloy C26000 and C66900 are both copper alloy grades. C66900 is the stronger of the two: yield strength 565 MPa (81.9 ksi) against 105 MPa (15.2 ksi) for C26000, about 5.4 times as much; tensile strength follows at 700 MPa (102 ksi) vs 325 MPa (47.1 ksi). In exchange, C26000 is the more ductile: elongation 62% versus 7% for C66900, and C66900 is harder (185 HB vs 55 HB). C66900 is lighter (8.1 g/cm³ vs 8.53 g/cm³ for C26000) and C26000 runs hotter in service (200°C vs 150°C continuous).

C26000Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C66900Choose it when strength drives the design, or when weight is the constraint.

C26000 vs C66900: properties

C26000C66900

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

110 GPa16 Msi
105 GPa15.2 Msi

Shear Modulus

41 GPa5.9 Msi
39 GPa5.7 Msi

Bulk Modulus

115 GPa16.7 Msi
105 GPa15.2 Msi

Poisson's Ratio

0.35
0.33

Tensile Strength (Ultimate)

325 MPa47.1 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

105 MPa15.2 ksi
565 MPa81.9 ksi

Elongation at Break

62%
7%

Shear Strength

234 MPa33.9 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

97 MPa14.1 ksi
260 MPa37.7 ksi

Hardness, Brinell

55 HB
185 HB

Hardness, Vickers

60 HV
195 HV

Hardness, Rockwell B

—
88 HRB

Physical

Density and transition temperatures.

Density

8.53 g/cm³0.31 lb/in³
8.1 g/cm³0.29 lb/in³

Melting Point (Solidus)

915°C1,679 °F
880°C1,616 °F

Liquidus Temperature

955°C1,751 °F
920°C1,688 °F

Thermal

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

Thermal Conductivity

121 W/m·K69.9 BTU/hr·ft·°F
27 W/m·K15.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

19.9 µm/m·K11.1 µin/in·°F
20 µm/m·K11.1 µin/in·°F

Latent Heat of Fusion

165 J/g70.9 BTU/lb
175 J/g75.2 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

28 % IACS
4.5 % IACS

Electrical Resistivity

6.2×10⁻⁸ Ω·m2.44 µΩ·in
3.8×10⁻⁷ Ω·m15 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.3 V

Corrosion Resistance

50 / 100
62 / 100

Manufacturability

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

Formability (cold)

98 / 100
25 / 100

Castability

25 / 100
40 / 100

Brazeability / Solderability

90 / 100
60 / 100

Polishability

85 / 100
80 / 100

Same in both: Machinability 30 / 100 · Machinability Rating (AISI 1212 = 100 %) 30% · Weldability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

250 L/kg30 gal/lb
400 L/kg47.9 gal/lb

Typical Recycled Content

45%
40%

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.5 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

38 kN·m/kg
86 kN·m/kg

Specific Stiffness (E / density)

12.9 MN·m/kg
13 MN·m/kg

Modulus of Resilience

50 kJ/m³
1,520 kJ/m³

Thermal Diffusivity

37.8 mm²/s
8.8 mm²/s

Thermal Shock Resistance Index

18
9

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 scaleC26000C66900

Manufacturing and finishing

CapabilityC26000C66900
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$$$ High$$$$ High
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
Chrome PlatingYes—
ElectropolishingYes—
Nickel PlatingYes—
PaintingYes—
Tin PlatingYes—

They share 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.

C26000 vs C66900 — frequently asked

Is C66900 stronger than C26000?

Yes. C66900 has a typical yield strength of 565 MPa (81.9 ksi) against 105 MPa (15.2 ksi) for C26000 — about 5.4 times as much. Tensile strength is 700 MPa (102 ksi) vs 325 MPa (47.1 ksi).

Which is cheaper, C26000 or C66900?

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.

When should I choose C26000 over C66900?

Pick C26000 when the part is bent, formed or impact-loaded, or when the part sees heat. Pick C66900 when strength drives the design, or when weight is the constraint.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C26000 and C66900 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.