Copper Alloy ERCuSi-A vs ERCuSn-A
Copper Alloy · grade comparison
Copper Alloy ERCuSi-A and ERCuSn-A are both copper alloy grades. ERCuSi-A is the stronger of the two: yield strength 195 MPa (28.3 ksi) against 165 MPa (23.9 ksi) for ERCuSn-A, about 18% more; tensile strength follows at 350 MPa (50.8 ksi) vs 330 MPa (47.9 ksi). ERCuSi-A is harder — 85 HB against 80 HB for ERCuSn-A — which matters for wear surfaces and threads. ERCuSi-A is lighter (8.53 g/cm³ vs 8.8 g/cm³ for ERCuSn-A) and ERCuSn-A is stiffer (110 GPa vs 103 GPa). On the shop floor, ERCuSi-A welds better (excellent vs good) and ERCuSn-A forms better (80 vs 70 out of 100).
ERCuSi-AChoose it when strength drives the design, or when surface hardness matters.
ERCuSi-A 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
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
Compressive Strength
Same in both: Bulk Modulus 115 GPa16.7 Msi · Hardness, Rockwell B 45 HRB
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
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 380 J/kg·K0.09 BTU/lb·°F · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 72 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 320 L/kg38.3 gal/lb
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 | ERCuSi-A | ERCuSn-A |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
ERCuSi-A vs ERCuSn-A — frequently asked
Is ERCuSi-A stronger than ERCuSn-A?
Yes. ERCuSi-A has a typical yield strength of 195 MPa (28.3 ksi) against 165 MPa (23.9 ksi) for ERCuSn-A — about 18% more. Tensile strength is 350 MPa (50.8 ksi) vs 330 MPa (47.9 ksi).
Which is cheaper, ERCuSi-A or ERCuSn-A?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, ERCuSi-A or ERCuSn-A?
ERCuSi-A. Its weldability rates excellent (90/100) against good (60/100) for ERCuSn-A.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ERCuSi-A 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.