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Copper Alloy C55281 vs ERCuAl-A2

Copper Alloy · grade comparison

Copper Alloy C55281 and ERCuAl-A2 are both copper alloy grades. ERCuAl-A2 is the stronger of the two: yield strength 270 MPa (39.2 ksi) against 170 MPa (24.7 ksi) for C55281, about 59% more; tensile strength follows at 585 MPa (84.8 ksi) vs 250 MPa (36.3 ksi). ERCuAl-A2 is the more ductile: elongation 25% versus 6% for C55281, and ERCuAl-A2 is harder (150 HB vs 85 HB). ERCuAl-A2 is lighter (7.58 g/cm³ vs 8.1 g/cm³ for C55281) and ERCuAl-A2 is stiffer (117 GPa vs 105 GPa).

ERCuAl-A2Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C55281 vs ERCuAl-A2: properties

C55281ERCuAl-A2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
117 GPa17 Msi

Shear Modulus

40 GPa5.8 Msi
44 GPa6.4 Msi

Poisson's Ratio

0.34
0.32

Tensile Strength (Ultimate)

250 MPa36.3 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
270 MPa39.2 ksi

Elongation at Break

6%
25%

Shear Strength

170 MPa24.7 ksi
350 MPa50.8 ksi

Hardness, Brinell

85 HB
150 HB

Fatigue Strength (Endurance Limit)

—
200 MPa29 ksi

Charpy V-Notch Impact (RT)

—
40 J29.5 ft·lbf

Hardness, Rockwell B

—
82 HRB

Hardness, Vickers

—
158 HV

Same in both: Bulk Modulus 115 GPa16.7 Msi

Physical

Density and transition temperatures.

Density

8.1 g/cm³0.29 lb/in³
7.58 g/cm³0.27 lb/in³

Melting Point (Solidus)

645°C1,193 °F
1,030°C1,886 °F

Liquidus Temperature

802°C1,476 °F
1,046°C1,915 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
59 W/m·K34.1 BTU/hr·ft·°F

Specific Heat Capacity

380 J/kg·K0.09 BTU/lb·°F
419 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

17 µm/m·K9.4 µin/in·°F
16.2 µm/m·K9 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
300°C572 °F

Min Service Temperature

-100°C-148 °F
-196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
13 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
1.33×10⁻⁷ Ω·m5.24 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.2 V
-0.31 V

Corrosion Resistance

55 / 100
74 / 100

Manufacturability

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

Formability (cold)

35 / 100
45 / 100

Castability

80 / 100
65 / 100

Brazeability / Solderability

95 / 100
35 / 100

Polishability

60 / 100
68 / 100

Machinability

—
32 / 100

Machinability Rating (AISI 1212 = 100 %)

—
30%

Weldability

—
72 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

125 MJ/kg53,740 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

11 kg CO₂/kg
3.9 kg CO₂/kg

Embodied Water

350 L/kg41.9 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

30%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
77 kN·m/kg

Specific Stiffness (E / density)

13 MN·m/kg
15.4 MN·m/kg

Modulus of Resilience

138 kJ/m³
312 kJ/m³

Thermal Diffusivity

16.2 mm²/s
18.6 mm²/s

Thermal Shock Resistance Index

7
18

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 scaleERCuAl-A2C55281

Manufacturing and finishing

CapabilityC55281ERCuAl-A2
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.

C55281 vs ERCuAl-A2 — frequently asked

Is ERCuAl-A2 stronger than C55281?

Yes. ERCuAl-A2 has a typical yield strength of 270 MPa (39.2 ksi) against 170 MPa (24.7 ksi) for C55281 — about 59% more. Tensile strength is 585 MPa (84.8 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, C55281 or ERCuAl-A2?

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 C55281 over ERCuAl-A2?

Pick ERCuAl-A2 when strength drives the design, or when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C55281 and ERCuAl-A2 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.