Copper Alloy C55281 vs ERCu
Copper Alloy · grade comparison
Copper Alloy C55281 and ERCu are both copper alloy grades. C55281 is the stronger of the two: yield strength 170 MPa (24.7 ksi) against 80 MPa (11.6 ksi) for ERCu, about 113% more; tensile strength follows at 250 MPa (36.3 ksi) vs 225 MPa (32.6 ksi). In exchange, ERCu is the more ductile: elongation 35% versus 6% for C55281, and C55281 is harder (85 HB vs 55 HB). C55281 is lighter (8.1 g/cm³ vs 8.9 g/cm³ for ERCu) and ERCu is stiffer (115 GPa vs 105 GPa).
C55281Choose it when strength drives the design, or when weight is the constraint.
ERCuChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C55281 vs ERCu: 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)
Elongation at Break
Shear Strength
Hardness, Brinell
Reduction in Area
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Poisson's Ratio 0.34
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.
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
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 | C55281 | ERCu |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
C55281 vs ERCu — frequently asked
Is C55281 stronger than ERCu?
Yes. C55281 has a typical yield strength of 170 MPa (24.7 ksi) against 80 MPa (11.6 ksi) for ERCu — about 113% more. Tensile strength is 250 MPa (36.3 ksi) vs 225 MPa (32.6 ksi).
Which is cheaper, C55281 or ERCu?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose C55281 over ERCu?
Pick C55281 when strength drives the design, or when weight is the constraint. Pick ERCu when the part is bent, formed or impact-loaded, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C55281 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.