Copper Alloy BCu-2 vs ERCuSn-A
Copper Alloy · grade comparison
Copper Alloy BCu-2 and ERCuSn-A are both copper alloy grades. ERCuSn-A is the stronger of the two: yield strength 165 MPa (23.9 ksi) against 65 MPa (9.43 ksi) for BCu-2, about 154% more; tensile strength follows at 330 MPa (47.9 ksi) vs 200 MPa (29 ksi). ERCuSn-A is harder — 80 HB against 45 HB for BCu-2 — which matters for wear surfaces and threads. BCu-2 runs hotter in service (350°C vs 200°C continuous) and BCu-2 conducts heat better (346 W/m·K vs 69 W/m·K). On the shop floor, ERCuSn-A welds better (good vs fair) and BCu-2 forms better (excellent vs very good).
BCu-2Choose it when the part sees heat.
ERCuSn-AChoose it when strength drives the design, or when surface hardness matters.
BCu-2 vs ERCuSn-A: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Hardness, Rockwell B
Same in both: Poisson's Ratio 0.34 · Elongation at Break 35%
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 20% · Castability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | BCu-2 | ERCuSn-A |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
BCu-2 vs ERCuSn-A — frequently asked
Is ERCuSn-A stronger than BCu-2?
Yes. ERCuSn-A has a typical yield strength of 165 MPa (23.9 ksi) against 65 MPa (9.43 ksi) for BCu-2 — about 154% more. Tensile strength is 330 MPa (47.9 ksi) vs 200 MPa (29 ksi).
Which is cheaper, BCu-2 or ERCuSn-A?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, BCu-2 or ERCuSn-A?
ERCuSn-A, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for BCu-2; for welding the order is ERCuSn-A first (good, 60/100) then BCu-2 (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in BCu-2 and ERCuSn-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.