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Copper Alloy C55280 vs ERCuSi-A

Copper Alloy · grade comparison

Copper Alloy C55280 and ERCuSi-A are both copper alloy grades. ERCuSi-A is the stronger of the two: tensile strength 350 MPa (50.8 ksi) against 250 MPa (36.3 ksi) for C55280, about 40% more. ERCuSi-A is the more ductile: elongation 38% versus 5% for C55280, and C55280 is harder (90 HB vs 85 HB). C55280 is lighter (8.15 g/cm³ vs 8.53 g/cm³ for ERCuSi-A) and ERCuSi-A runs hotter in service (200°C vs 150°C continuous). On the shop floor, ERCuSi-A welds better (excellent vs poor).

C55280Choose it when weight is the constraint.

ERCuSi-AChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C55280 vs ERCuSi-A: properties

C55280ERCuSi-A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

100 GPa14.5 Msi
103 GPa14.9 Msi

Shear Modulus

38 GPa5.5 Msi
38.5 GPa5.6 Msi

Poisson's Ratio

0.34
0.35

Tensile Strength (Ultimate)

250 MPa36.3 ksi
350 MPa50.8 ksi

Elongation at Break

5%
38%

Shear Strength

170 MPa24.7 ksi
215 MPa31.2 ksi

Hardness, Brinell

90 HB
85 HB

Bulk Modulus

—
115 GPa16.7 Msi

Yield Strength (0.2% offset)

—
195 MPa28.3 ksi

Reduction in Area

—
45%

Fatigue Strength (Endurance Limit)

—
145 MPa21 ksi

Charpy V-Notch Impact (RT)

—
60 J44.3 ft·lbf

Hardness, Rockwell B

—
45 HRB

Hardness, Vickers

—
90 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

643°C1,189 °F
970°C1,778 °F

Liquidus Temperature

788°C1,450 °F
1,025°C1,877 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

17.5 µm/m·K9.7 µin/in·°F
18 µm/m·K10 µin/in·°F

Latent Heat of Fusion

200 J/g86 BTU/lb
205 J/g88.1 BTU/lb

Max Service Temperature (continuous)

150°C302 °F
200°C392 °F

Min Service Temperature

-70°C-94 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 380 J/kg·K0.09 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
7 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
2.46×10⁻⁷ Ω·m9.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.26 V

Corrosion Resistance

60 / 100
72 / 100

Manufacturability

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

Machinability

30 / 100
33 / 100

Weldability

15 / 100
90 / 100

Formability (cold)

25 / 100
70 / 100

Castability

75 / 100
60 / 100

Brazeability / Solderability

95 / 100
92 / 100

Polishability

50 / 100
75 / 100

Machinability Rating (AISI 1212 = 100 %)

—
30%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

90 MJ/kg38,693 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

6 kg CO₂/kg
3.8 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
320 L/kg38.3 gal/lb

Typical Recycled Content

30%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
41 kN·m/kg

Specific Stiffness (E / density)

12.3 MN·m/kg
12.1 MN·m/kg

Thermal Diffusivity

16.1 mm²/s
11.1 mm²/s

Same in both: Thermal Shock Resistance Index 7

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 scaleERCuSi-A

Manufacturing and finishing

CapabilityC55280ERCuSi-A
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.

C55280 vs ERCuSi-A — frequently asked

Is ERCuSi-A stronger than C55280?

Yes. ERCuSi-A has a typical tensile strength of 350 MPa (50.8 ksi) against 250 MPa (36.3 ksi) for C55280 — about 40% more.

Which is cheaper, C55280 or ERCuSi-A?

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, C55280 or ERCuSi-A?

ERCuSi-A. Its weldability rates excellent (90/100) against poor (15/100) for C55280.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C55280 and ERCuSi-A 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.