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Copper Alloy C72700 vs C74400

Copper Alloy · grade comparison

Copper Alloy C72700 and C74400 are both copper alloy grades. C72700 is the stronger of the two: yield strength 730 MPa (106 ksi) against 440 MPa (63.8 ksi) for C74400, about 66% more; tensile strength follows at 800 MPa (116 ksi) vs 515 MPa (74.7 ksi). In exchange, C74400 is the more ductile: elongation 12% versus 8% for C72700, and C72700 is harder (250 HV vs 145 HV). C72700 is stiffer (131 GPa vs 124 GPa) and C74400 conducts heat better (45 W/m·K vs 33 W/m·K). On the shop floor, C74400 welds better (52 vs 35 out of 100).

C72700Choose it when strength drives the design.

C74400Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

C72700 vs C74400: properties

C72700C74400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

131 GPa19 Msi
124 GPa18 Msi

Shear Modulus

50 GPa7.3 Msi
46 GPa6.7 Msi

Bulk Modulus

125 GPa18.1 Msi
130 GPa18.9 Msi

Poisson's Ratio

0.31
0.34

Tensile Strength (Ultimate)

800 MPa116 ksi
515 MPa74.7 ksi

Yield Strength (0.2% offset)

730 MPa106 ksi
440 MPa63.8 ksi

Elongation at Break

8%
12%

Shear Strength

480 MPa69.6 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
200 MPa29 ksi

Hardness, Rockwell B

98 HRB
75 HRB

Hardness, Rockwell C

23 HRC
—

Hardness, Vickers

250 HV
145 HV

Hardness, Brinell

—
138 HB

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,060°C1,940 °F
1,020°C1,868 °F

Liquidus Temperature

1,120°C2,048 °F
1,065°C1,949 °F

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16.5 µm/m·K9.2 µin/in·°F
16.2 µm/m·K9 µin/in·°F

Same in both: Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F · Latent Heat of Fusion 200 J/g86 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

11 % IACS
9.8 % IACS

Electrical Resistivity

1.57×10⁻⁷ Ω·m6.18 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)

-0.25 V
-0.2 V

Corrosion Resistance

72 / 100
62 / 100

Manufacturability

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

Machinability

30 / 100
25 / 100

Weldability

35 / 100
52 / 100

Formability (cold)

45 / 100
70 / 100

Brazeability / Solderability

70 / 100
85 / 100

Polishability

80 / 100
90 / 100

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

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

68 MJ/kg29,235 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

4.8 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
300 L/kg35.9 gal/lb

Typical Recycled Content

25%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

90 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

14.8 MN·m/kg
14.3 MN·m/kg

Modulus of Resilience

2,034 kJ/m³
781 kJ/m³

Thermal Diffusivity

9.9 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 scaleC74400C72700

Manufacturing and finishing

CapabilityC72700C74400
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.

C72700 vs C74400 — frequently asked

Is C72700 stronger than C74400?

Yes. C72700 has a typical yield strength of 730 MPa (106 ksi) against 440 MPa (63.8 ksi) for C74400 — about 66% more. Tensile strength is 800 MPa (116 ksi) vs 515 MPa (74.7 ksi).

Which is cheaper, C72700 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 is easier to machine, C72700 or C74400?

C72700, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for C74400; for welding the order is C74400 first (fair, 52/100) then C72700 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C72700 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.