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Copper Alloy BCu-2 vs ERCuAl-A3

Copper Alloy · grade comparison

Copper Alloy BCu-2 and ERCuAl-A3 are both copper alloy grades. ERCuAl-A3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 65 MPa (9.43 ksi) for BCu-2, about 5.3 times as much; tensile strength follows at 690 MPa (100 ksi) vs 200 MPa (29 ksi). In exchange, BCu-2 is the more ductile: elongation 35% versus 8% for ERCuAl-A3, and ERCuAl-A3 is harder (210 HB vs 45 HB). ERCuAl-A3 is lighter (7.5 g/cm³ vs 8.92 g/cm³ for BCu-2) and BCu-2 runs hotter in service (350°C vs 300°C continuous). On the shop floor, ERCuAl-A3 welds better (good vs fair).

BCu-2Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

ERCuAl-A3Choose it when strength drives the design, or when weight is the constraint.

BCu-2 vs ERCuAl-A3: properties

BCu-2ERCuAl-A3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

140 GPa20.3 Msi
110 GPa16 Msi

Poisson's Ratio

0.34
0.32

Tensile Strength (Ultimate)

200 MPa29 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

65 MPa9.4 ksi
345 MPa50 ksi

Elongation at Break

35%
8%

Reduction in Area

45%
10%

Compressive Strength

220 MPa31.9 ksi
—

Shear Strength

145 MPa21 ksi
410 MPa59.5 ksi

Fatigue Strength (Endurance Limit)

65 MPa9.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
—

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

45 HB
210 HB

Hardness, Vickers

48 HV
220 HV

Hardness, Rockwell C

—
20 HRC

Same in both: Elastic (Young's) Modulus 115 GPa16.7 Msi · Shear Modulus 44 GPa6.4 Msi

Physical

Density and transition temperatures.

Density

8.92 g/cm³0.32 lb/in³
7.5 g/cm³0.27 lb/in³

Melting Point (Solidus)

1,083°C1,981 °F
1,030°C1,886 °F

Liquidus Temperature

1,083°C1,981 °F
1,050°C1,922 °F

Thermal

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

Thermal Conductivity

346 W/m·K200 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

385 J/kg·K0.09 BTU/lb·°F
400 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

205 J/g88.1 BTU/lb
210 J/g90.3 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
300°C572 °F

Min Service Temperature

-196°C-321 °F
-100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

90 % IACS
9 % IACS

Electrical Resistivity

1.9×10⁻⁸ Ω·m0.748 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
74 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.28 V

Manufacturability

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

Machinability

25 / 100
28 / 100

Weldability

45 / 100
60 / 100

Formability (cold)

90 / 100
25 / 100

Castability

55 / 100
65 / 100

Brazeability / Solderability

95 / 100
30 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 20% · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

50 MJ/kg21,496 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

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

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

22 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

12.9 MN·m/kg
15.3 MN·m/kg

Modulus of Resilience

18 kJ/m³
518 kJ/m³

Thermal Diffusivity

100.8 mm²/s
15.3 mm²/s

Thermal Shock Resistance Index

34
17

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-A3BCu-2

Manufacturing and finishing

CapabilityBCu-2ERCuAl-A3
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.

BCu-2 vs ERCuAl-A3 — frequently asked

Is ERCuAl-A3 stronger than BCu-2?

Yes. ERCuAl-A3 has a typical yield strength of 345 MPa (50 ksi) against 65 MPa (9.43 ksi) for BCu-2 — about 5.3 times as much. Tensile strength is 690 MPa (100 ksi) vs 200 MPa (29 ksi).

Which is cheaper, BCu-2 or ERCuAl-A3?

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, BCu-2 or ERCuAl-A3?

ERCuAl-A3. Its weldability rates good (60/100) against fair (45/100) for BCu-2.

Ready to make it?

Upload a CAD file and FabDigit prices the part in BCu-2 and ERCuAl-A3 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.