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Copper Alloy C81400 vs Cu-ETP1

Copper Alloy · grade comparison

Copper Alloy C81400 and Cu-ETP1 are both copper alloy grades. C81400 is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 70 MPa (10.2 ksi) for Cu-ETP1, about 3.6 times as much; tensile strength follows at 350 MPa (50.8 ksi) vs 220 MPa (31.9 ksi). In exchange, Cu-ETP1 is the more ductile: elongation 40% versus 11% for C81400, and C81400 is harder (110 HB vs 45 HB). C81400 runs hotter in service (350°C vs 200°C continuous) and Cu-ETP1 conducts heat better (394 W/m·K vs 259 W/m·K). On the shop floor, C81400 machines more easily (good vs poor) and Cu-ETP1 welds better (50 vs 40 out of 100).

C81400Choose it when strength drives the design, or when the part sees heat.

Cu-ETP1Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

C81400 vs Cu-ETP1: properties

C81400Cu-ETP1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

138 GPa20 Msi
140 GPa20.3 Msi

Poisson's Ratio

0.33
0.34

Tensile Strength (Ultimate)

350 MPa50.8 ksi
220 MPa31.9 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
70 MPa10.2 ksi

Elongation at Break

11%
40%

Shear Strength

235 MPa34.1 ksi
150 MPa21.8 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
75 MPa10.9 ksi

Hardness, Brinell

110 HB
45 HB

Hardness, Rockwell B

69 HRB
—

Hardness, Vickers

115 HV
50 HV

Reduction in Area

—
70%

Charpy V-Notch Impact (RT)

—
60 J44.3 ft·lbf

Same in both: Elastic (Young's) Modulus 117 GPa17 Msi · Shear Modulus 44 GPa6.4 Msi

Physical

Density and transition temperatures.

Density

8.83 g/cm³0.32 lb/in³
8.93 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,075°C1,967 °F
1,065°C1,949 °F

Liquidus Temperature

1,085°C1,985 °F
1,083°C1,981 °F

Thermal

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

Thermal Conductivity

259 W/m·K150 BTU/hr·ft·°F
394 W/m·K228 BTU/hr·ft·°F

Specific Heat Capacity

376 J/kg·K0.09 BTU/lb·°F
385 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

16.6 µm/m·K9.2 µin/in·°F
17 µm/m·K9.4 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
200°C392 °F

Min Service Temperature

-200°C-328 °F
-250°C-418 °F

Same in both: Latent Heat of Fusion 205 J/g88.1 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

70 % IACS
101.5 % IACS

Electrical Resistivity

2.46×10⁻⁸ Ω·m0.969 µΩ·in
1.7×10⁻⁸ Ω·m0.669 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.25 V

Corrosion Resistance

60 / 100
65 / 100

Manufacturability

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

Machinability

55 / 100
30 / 100

Weldability

40 / 100
50 / 100

Castability

60 / 100
45 / 100

Brazeability / Solderability

60 / 100
85 / 100

Polishability

70 / 100
80 / 100

Formability (cold)

—
95 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 20%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

57 MJ/kg24,506 BTU/lb
53 MJ/kg22,786 BTU/lb

Embodied Carbon (primary production)

3.9 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

260 L/kg31.2 gal/lb
350 L/kg41.9 gal/lb

Typical Recycled Content

30%
10%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

40 kN·m/kg
25 kN·m/kg

Specific Stiffness (E / density)

13.3 MN·m/kg
13.1 MN·m/kg

Modulus of Resilience

267 kJ/m³
21 kJ/m³

Thermal Diffusivity

78 mm²/s
114.6 mm²/s

Thermal Shock Resistance Index

47
44

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 scaleC81400Cu-ETP1

Manufacturing and finishing

CapabilityC81400Cu-ETP1
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.

C81400 vs Cu-ETP1 — frequently asked

Is C81400 stronger than Cu-ETP1?

Yes. C81400 has a typical yield strength of 250 MPa (36.3 ksi) against 70 MPa (10.2 ksi) for Cu-ETP1 — about 3.6 times as much. Tensile strength is 350 MPa (50.8 ksi) vs 220 MPa (31.9 ksi).

Which is cheaper, C81400 or Cu-ETP1?

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 is easier to machine, C81400 or Cu-ETP1?

C81400. Its machinability rates good (55/100) against poor (30/100) for Cu-ETP1; for welding the order is Cu-ETP1 first (fair, 50/100) then C81400 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C81400 and Cu-ETP1 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.