Copper Alloy ERCu vs ERCuAl-A3
Copper Alloy · grade comparison
Copper Alloy ERCu and ERCuAl-A3 are both copper alloy grades. ERCuAl-A3 is the stronger of the two: yield strength 345 MPa (50 ksi) against 80 MPa (11.6 ksi) for ERCu, about 4.3 times as much; tensile strength follows at 690 MPa (100 ksi) vs 225 MPa (32.6 ksi). In exchange, ERCu is the more ductile: elongation 35% versus 8% for ERCuAl-A3, and ERCuAl-A3 is harder (210 HB vs 55 HB). ERCuAl-A3 is lighter (7.5 g/cm³ vs 8.9 g/cm³ for ERCu) and ERCuAl-A3 runs hotter in service (300°C vs 250°C continuous). On the shop floor, ERCu welds better (very good vs good).
ERCuChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
ERCuAl-A3Choose it when strength drives the design, or when weight is the constraint.
ERCu vs ERCuAl-A3: 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.
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 115 GPa16.7 Msi · Shear Modulus 44 GPa6.4 Msi
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)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 20%
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 | ERCu | ERCuAl-A3 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
ERCu vs ERCuAl-A3 — frequently asked
Is ERCuAl-A3 stronger than ERCu?
Yes. ERCuAl-A3 has a typical yield strength of 345 MPa (50 ksi) against 80 MPa (11.6 ksi) for ERCu — about 4.3 times as much. Tensile strength is 690 MPa (100 ksi) vs 225 MPa (32.6 ksi).
Which is cheaper, ERCu or ERCuAl-A3?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, ERCu or ERCuAl-A3?
ERCu. Its weldability rates very good (78/100) against good (60/100) for ERCuAl-A3.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ERCu 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.