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Copper Alloy BCu-2 vs ERCu

Copper Alloy · grade comparison

Copper Alloy BCu-2 and ERCu are both copper alloy grades. ERCu is the stronger of the two: yield strength 80 MPa (11.6 ksi) against 65 MPa (9.43 ksi) for BCu-2, about 23% more; tensile strength follows at 225 MPa (32.6 ksi) vs 200 MPa (29 ksi). ERCu is harder — 55 HB against 45 HB for BCu-2 — which matters for wear surfaces and threads. BCu-2 runs hotter in service (350°C vs 250°C continuous) and BCu-2 conducts heat better (346 W/m·K vs 250 W/m·K). On the shop floor, ERCu welds better (very good vs fair).

BCu-2Choose it when the part sees heat.

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

BCu-2 vs ERCu: properties

BCu-2ERCu

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

200 MPa29 ksi
225 MPa32.6 ksi

Yield Strength (0.2% offset)

65 MPa9.4 ksi
80 MPa11.6 ksi

Reduction in Area

45%
60%

Compressive Strength

220 MPa31.9 ksi
—

Shear Strength

145 MPa21 ksi
150 MPa21.8 ksi

Fatigue Strength (Endurance Limit)

65 MPa9.4 ksi
70 MPa10.2 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
—

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

45 HB
55 HB

Hardness, Vickers

48 HV
58 HV

Same in both: Elastic (Young's) Modulus 115 GPa16.7 Msi · Shear Modulus 44 GPa6.4 Msi · Bulk Modulus 140 GPa20.3 Msi · Poisson's Ratio 0.34 · Elongation at Break 35%

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,083°C1,981 °F
1,065°C1,949 °F

Liquidus Temperature

1,083°C1,981 °F
1,080°C1,976 °F

Thermal

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

Thermal Conductivity

346 W/m·K200 BTU/hr·ft·°F
250 W/m·K144 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

350°C662 °F
250°C482 °F

Same in both: Specific Heat Capacity 385 J/kg·K0.09 BTU/lb·°F · Latent Heat of Fusion 205 J/g88.1 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

90 % IACS
40 % IACS

Electrical Resistivity

1.9×10⁻⁸ Ω·m0.748 µΩ·in
4.3×10⁻⁸ Ω·m1.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.3 V

Corrosion Resistance

58 / 100
62 / 100

Manufacturability

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

Machinability

25 / 100
30 / 100

Weldability

45 / 100
78 / 100

Formability (cold)

90 / 100
92 / 100

Castability

55 / 100
40 / 100

Brazeability / Solderability

95 / 100
92 / 100

Polishability

70 / 100
78 / 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
57 MJ/kg24,506 BTU/lb

Typical Recycled Content

30%
35%

Same in both: Embodied Carbon (primary production) 3.8 kg CO₂/kg · Embodied Water 250 L/kg30 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

22 kN·m/kg
25 kN·m/kg

Modulus of Resilience

18 kJ/m³
28 kJ/m³

Thermal Diffusivity

100.8 mm²/s
73 mm²/s

Thermal Shock Resistance Index

34
28

Same in both: Specific Stiffness (E / density) 12.9 MN·m/kg

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 scaleERCuBCu-2

Manufacturing and finishing

CapabilityBCu-2ERCu
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 ERCu — frequently asked

Is ERCu stronger than BCu-2?

Yes. ERCu has a typical yield strength of 80 MPa (11.6 ksi) against 65 MPa (9.43 ksi) for BCu-2 — about 23% more. Tensile strength is 225 MPa (32.6 ksi) vs 200 MPa (29 ksi).

Which is cheaper, BCu-2 or ERCu?

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 is easier to machine, BCu-2 or ERCu?

ERCu, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for BCu-2; for welding the order is ERCu first (very good, 78/100) then BCu-2 (fair, 45/100).

Ready to make it?

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