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Copper Alloy C70500 vs C74400

Copper Alloy · grade comparison

Copper Alloy C70500 and C74400 are both copper alloy grades. C74400 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 105 MPa (15.2 ksi) for C70500, about 4.2 times as much; tensile strength follows at 515 MPa (74.7 ksi) vs 275 MPa (39.9 ksi). In exchange, C70500 is the more ductile: elongation 40% versus 12% for C74400, and C74400 is harder (138 HB vs 55 HB). C70500 runs hotter in service (300°C vs 200°C continuous) and C70500 conducts heat better (90 W/m·K vs 45 W/m·K). On the shop floor, C70500 welds better (very good vs fair).

C70500Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C74400Choose it when strength drives the design.

C70500 vs C74400: properties

C70500C74400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

132 GPa19.1 Msi
130 GPa18.9 Msi

Tensile Strength (Ultimate)

275 MPa39.9 ksi
515 MPa74.7 ksi

Yield Strength (0.2% offset)

105 MPa15.2 ksi
440 MPa63.8 ksi

Elongation at Break

40%
12%

Reduction in Area

55%
—

Shear Strength

190 MPa27.6 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

100 MPa14.5 ksi
200 MPa29 ksi

Hardness, Brinell

55 HB
138 HB

Hardness, Vickers

58 HV
145 HV

Hardness, Rockwell B

—
75 HRB

Same in both: Elastic (Young's) Modulus 124 GPa18 Msi · Shear Modulus 46 GPa6.7 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

8.9 g/cm³0.32 lb/in³
8.7 g/cm³0.31 lb/in³

Melting Point (Solidus)

1,090°C1,994 °F
1,020°C1,868 °F

Liquidus Temperature

1,105°C2,021 °F
1,065°C1,949 °F

Thermal

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

Thermal Conductivity

90 W/m·K52 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

17.1 µm/m·K9.5 µin/in·°F
16.2 µm/m·K9 µin/in·°F

Latent Heat of Fusion

210 J/g90.3 BTU/lb
200 J/g86 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
200°C392 °F

Same in both: Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

25 % IACS
9.8 % IACS

Electrical Resistivity

6.9×10⁻⁸ Ω·m2.72 µΩ·in
1.76×10⁻⁷ Ω·m6.93 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.26 V
-0.2 V

Corrosion Resistance

58 / 100
62 / 100

Manufacturability

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

Machinability

22 / 100
25 / 100

Weldability

80 / 100
52 / 100

Formability (cold)

90 / 100
70 / 100

Polishability

70 / 100
90 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 20% · Brazeability / Solderability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

60 MJ/kg25,795 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

4 kg CO₂/kg
4.5 kg CO₂/kg

Same in both: Embodied Water 300 L/kg35.9 gal/lb · Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

13.9 MN·m/kg
14.3 MN·m/kg

Modulus of Resilience

44 kJ/m³
781 kJ/m³

Thermal Diffusivity

26.8 mm²/s
13.7 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleC74400C70500

Manufacturing and finishing

CapabilityC70500C74400
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.

C70500 vs C74400 — frequently asked

Is C74400 stronger than C70500?

Yes. C74400 has a typical yield strength of 440 MPa (63.8 ksi) against 105 MPa (15.2 ksi) for C70500 — about 4.2 times as much. Tensile strength is 515 MPa (74.7 ksi) vs 275 MPa (39.9 ksi).

Which is cheaper, C70500 or C74400?

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, C70500 or C74400?

C70500. Its weldability rates very good (80/100) against fair (52/100) for C74400.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C70500 and C74400 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.