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Copper Alloy ERCuAl-A2 vs ERCuSn-A

Copper Alloy · grade comparison

Copper Alloy ERCuAl-A2 and ERCuSn-A are both copper alloy grades. ERCuAl-A2 is the stronger of the two: yield strength 270 MPa (39.2 ksi) against 165 MPa (23.9 ksi) for ERCuSn-A, about 64% more; tensile strength follows at 585 MPa (84.8 ksi) vs 330 MPa (47.9 ksi). In exchange, ERCuSn-A is the more ductile: elongation 35% versus 25% for ERCuAl-A2, and ERCuAl-A2 is harder (150 HB vs 80 HB). ERCuAl-A2 is lighter (7.58 g/cm³ vs 8.8 g/cm³ for ERCuSn-A) and ERCuAl-A2 is stiffer (117 GPa vs 110 GPa). On the shop floor, ERCuAl-A2 welds better (very good vs good).

ERCuAl-A2Choose it when strength drives the design, or when weight is the constraint.

ERCuSn-AChoose it when the part is bent, formed or impact-loaded.

ERCuAl-A2 vs ERCuSn-A: properties

ERCuAl-A2ERCuSn-A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

117 GPa17 Msi
110 GPa16 Msi

Shear Modulus

44 GPa6.4 Msi
41 GPa5.9 Msi

Poisson's Ratio

0.32
0.34

Tensile Strength (Ultimate)

585 MPa84.8 ksi
330 MPa47.9 ksi

Yield Strength (0.2% offset)

270 MPa39.2 ksi
165 MPa23.9 ksi

Elongation at Break

25%
35%

Shear Strength

350 MPa50.8 ksi
230 MPa33.4 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
130 MPa18.9 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

150 HB
80 HB

Hardness, Rockwell B

82 HRB
45 HRB

Hardness, Vickers

158 HV
—

Compressive Strength

—
320 MPa46.4 ksi

Same in both: Bulk Modulus 115 GPa16.7 Msi

Physical

Density and transition temperatures.

Density

7.58 g/cm³0.27 lb/in³
8.8 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,030°C1,886 °F
950°C1,742 °F

Liquidus Temperature

1,046°C1,915 °F
1,050°C1,922 °F

Thermal

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

Thermal Conductivity

59 W/m·K34.1 BTU/hr·ft·°F
69 W/m·K39.9 BTU/hr·ft·°F

Specific Heat Capacity

419 J/kg·K0.1 BTU/lb·°F
380 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16.2 µm/m·K9 µin/in·°F
17.8 µm/m·K9.9 µin/in·°F

Latent Heat of Fusion

205 J/g88.1 BTU/lb
200 J/g86 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
200°C392 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

13 % IACS
15 % IACS

Electrical Resistivity

1.33×10⁻⁷ Ω·m5.24 µΩ·in
1.15×10⁻⁷ Ω·m4.53 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.31 V
-0.28 V

Corrosion Resistance

74 / 100
72 / 100

Manufacturability

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

Machinability

32 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
20%

Weldability

72 / 100
60 / 100

Formability (cold)

45 / 100
80 / 100

Castability

65 / 100
55 / 100

Brazeability / Solderability

35 / 100
80 / 100

Polishability

68 / 100
75 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

58 MJ/kg24,936 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

3.9 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
320 L/kg38.3 gal/lb

Same in both: Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

77 kN·m/kg
38 kN·m/kg

Specific Stiffness (E / density)

15.4 MN·m/kg
12.5 MN·m/kg

Modulus of Resilience

312 kJ/m³
124 kJ/m³

Thermal Diffusivity

18.6 mm²/s
20.6 mm²/s

Thermal Shock Resistance Index

18
12

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 scaleERCuAl-A2ERCuSn-A

Manufacturing and finishing

CapabilityERCuAl-A2ERCuSn-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.

ERCuAl-A2 vs ERCuSn-A — frequently asked

Is ERCuAl-A2 stronger than ERCuSn-A?

Yes. ERCuAl-A2 has a typical yield strength of 270 MPa (39.2 ksi) against 165 MPa (23.9 ksi) for ERCuSn-A — about 64% more. Tensile strength is 585 MPa (84.8 ksi) vs 330 MPa (47.9 ksi).

Which is cheaper, ERCuAl-A2 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, ERCuAl-A2 or ERCuSn-A?

ERCuAl-A2. Its weldability rates very good (72/100) against good (60/100) for ERCuSn-A.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ERCuAl-A2 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.