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Copper Alloy ERCuAl-A2 vs ERCuSi-A

Copper Alloy · grade comparison

Copper Alloy ERCuAl-A2 and ERCuSi-A are both copper alloy grades. ERCuAl-A2 is the stronger of the two: yield strength 270 MPa (39.2 ksi) against 195 MPa (28.3 ksi) for ERCuSi-A, about 38% more; tensile strength follows at 585 MPa (84.8 ksi) vs 350 MPa (50.8 ksi). In exchange, ERCuSi-A is the more ductile: elongation 38% versus 25% for ERCuAl-A2, and ERCuAl-A2 is harder (150 HB vs 85 HB). ERCuAl-A2 is lighter (7.58 g/cm³ vs 8.53 g/cm³ for ERCuSi-A) and ERCuAl-A2 is stiffer (117 GPa vs 103 GPa). On the shop floor, ERCuSi-A welds better (excellent vs very good).

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

ERCuSi-AChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

ERCuAl-A2 vs ERCuSi-A: properties

ERCuAl-A2ERCuSi-A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

117 GPa17 Msi
103 GPa14.9 Msi

Shear Modulus

44 GPa6.4 Msi
38.5 GPa5.6 Msi

Poisson's Ratio

0.32
0.35

Tensile Strength (Ultimate)

585 MPa84.8 ksi
350 MPa50.8 ksi

Yield Strength (0.2% offset)

270 MPa39.2 ksi
195 MPa28.3 ksi

Elongation at Break

25%
38%

Shear Strength

350 MPa50.8 ksi
215 MPa31.2 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
145 MPa21 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

150 HB
85 HB

Hardness, Rockwell B

82 HRB
45 HRB

Hardness, Vickers

158 HV
90 HV

Reduction in Area

—
45%

Same in both: Bulk Modulus 115 GPa16.7 Msi

Physical

Density and transition temperatures.

Density

7.58 g/cm³0.27 lb/in³
8.53 g/cm³0.31 lb/in³

Melting Point (Solidus)

1,030°C1,886 °F
970°C1,778 °F

Liquidus Temperature

1,046°C1,915 °F
1,025°C1,877 °F

Thermal

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

Thermal Conductivity

59 W/m·K34.1 BTU/hr·ft·°F
36 W/m·K20.8 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
18 µm/m·K10 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
200°C392 °F

Same in both: Latent Heat of Fusion 205 J/g88.1 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

13 % IACS
7 % IACS

Electrical Resistivity

1.33×10⁻⁷ Ω·m5.24 µΩ·in
2.46×10⁻⁷ Ω·m9.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.31 V
-0.26 V

Corrosion Resistance

74 / 100
72 / 100

Manufacturability

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

Machinability

32 / 100
33 / 100

Weldability

72 / 100
90 / 100

Formability (cold)

45 / 100
70 / 100

Castability

65 / 100
60 / 100

Brazeability / Solderability

35 / 100
92 / 100

Polishability

68 / 100
75 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 30%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

58 MJ/kg24,936 BTU/lb
57 MJ/kg24,506 BTU/lb

Embodied Carbon (primary production)

3.9 kg CO₂/kg
3.8 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

77 kN·m/kg
41 kN·m/kg

Specific Stiffness (E / density)

15.4 MN·m/kg
12.1 MN·m/kg

Modulus of Resilience

312 kJ/m³
185 kJ/m³

Thermal Diffusivity

18.6 mm²/s
11.1 mm²/s

Thermal Shock Resistance Index

18
7

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 scaleERCuSi-AERCuAl-A2

Manufacturing and finishing

CapabilityERCuAl-A2ERCuSi-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 ERCuSi-A — frequently asked

Is ERCuAl-A2 stronger than ERCuSi-A?

Yes. ERCuAl-A2 has a typical yield strength of 270 MPa (39.2 ksi) against 195 MPa (28.3 ksi) for ERCuSi-A — about 38% more. Tensile strength is 585 MPa (84.8 ksi) vs 350 MPa (50.8 ksi).

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

ERCuSi-A. Its weldability rates excellent (90/100) against very good (72/100) for ERCuAl-A2.

Ready to make it?

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