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Copper Alloy BCu-2 vs ERCuNi

Copper Alloy · grade comparison

Copper Alloy BCu-2 and ERCuNi are both copper alloy grades. ERCuNi is the stronger of the two: yield strength 220 MPa (31.9 ksi) against 65 MPa (9.43 ksi) for BCu-2, about 3.4 times as much; tensile strength follows at 400 MPa (58 ksi) vs 200 MPa (29 ksi). ERCuNi is harder — 90 HB against 45 HB for BCu-2 — which matters for wear surfaces and threads. ERCuNi is stiffer (152 GPa vs 115 GPa) and BCu-2 runs hotter in service (350°C vs 315°C continuous). On the shop floor, ERCuNi welds better (very good vs fair) and BCu-2 forms better (excellent vs very good).

BCu-2Choose it when the part sees heat.

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

BCu-2 vs ERCuNi: properties

BCu-2ERCuNi

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

115 GPa16.7 Msi
152 GPa22 Msi

Shear Modulus

44 GPa6.4 Msi
57 GPa8.3 Msi

Bulk Modulus

140 GPa20.3 Msi
158 GPa22.9 Msi

Tensile Strength (Ultimate)

200 MPa29 ksi
400 MPa58 ksi

Yield Strength (0.2% offset)

65 MPa9.4 ksi
220 MPa31.9 ksi

Elongation at Break

35%
32%

Compressive Strength

220 MPa31.9 ksi
—

Shear Strength

145 MPa21 ksi
260 MPa37.7 ksi

Fatigue Strength (Endurance Limit)

65 MPa9.4 ksi
130 MPa18.9 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
—

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

45 HB
90 HB

Hardness, Vickers

48 HV
95 HV

Hardness, Rockwell B

—
52 HRB

Same in both: Poisson's Ratio 0.34 · Reduction in Area 45%

Physical

Density and transition temperatures.

Density

8.92 g/cm³0.32 lb/in³
8.94 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,083°C1,981 °F
1,170°C2,138 °F

Liquidus Temperature

1,083°C1,981 °F
1,240°C2,264 °F

Thermal

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

Thermal Conductivity

346 W/m·K200 BTU/hr·ft·°F
28 W/m·K16.2 BTU/hr·ft·°F

Specific Heat Capacity

385 J/kg·K0.09 BTU/lb·°F
377 J/kg·K0.09 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
315°C599 °F

Min Service Temperature

-196°C-321 °F
-198°C-324 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

90 % IACS
4.6 % IACS

Electrical Resistivity

1.9×10⁻⁸ Ω·m0.748 µΩ·in
3.75×10⁻⁷ Ω·m14.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.27 V

Corrosion Resistance

58 / 100
74 / 100

Manufacturability

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

Machinability

25 / 100
28 / 100

Weldability

45 / 100
78 / 100

Formability (cold)

90 / 100
75 / 100

Castability

55 / 100
45 / 100

Brazeability / Solderability

95 / 100
70 / 100

Polishability

70 / 100
72 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 20%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

50 MJ/kg21,496 BTU/lb
78 MJ/kg33,534 BTU/lb

Embodied Carbon (primary production)

3.8 kg CO₂/kg
6.2 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
260 L/kg31.2 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

22 kN·m/kg
45 kN·m/kg

Specific Stiffness (E / density)

12.9 MN·m/kg
17 MN·m/kg

Modulus of Resilience

18 kJ/m³
159 kJ/m³

Thermal Diffusivity

100.8 mm²/s
8.3 mm²/s

Thermal Shock Resistance Index

34
5

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 scaleERCuNiBCu-2

Manufacturing and finishing

CapabilityBCu-2ERCuNi
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 ERCuNi — frequently asked

Is ERCuNi stronger than BCu-2?

Yes. ERCuNi has a typical yield strength of 220 MPa (31.9 ksi) against 65 MPa (9.43 ksi) for BCu-2 — about 3.4 times as much. Tensile strength is 400 MPa (58 ksi) vs 200 MPa (29 ksi).

Which is cheaper, BCu-2 or ERCuNi?

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 ERCuNi?

ERCuNi. Its weldability rates very good (78/100) against fair (45/100) for BCu-2.

Ready to make it?

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