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Copper Alloy C72650 vs C74400

Copper Alloy · grade comparison

Copper Alloy C72650 and C74400 are both copper alloy grades. C72650 is the stronger of the two: yield strength 745 MPa (108 ksi) against 440 MPa (63.8 ksi) for C74400, about 69% more; tensile strength follows at 795 MPa (115 ksi) vs 515 MPa (74.7 ksi). In exchange, C74400 is the more ductile: elongation 12% versus 8% for C72650, and C72650 is harder (285 HB vs 138 HB). C72650 is stiffer (135 GPa vs 124 GPa) and C72650 runs hotter in service (250°C vs 200°C continuous). On the shop floor, C72650 machines more easily (very good vs poor) and C74400 welds better (52 vs 35 out of 100).

C72650Choose it when strength drives the design, or when the part sees heat.

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

C72650 vs C74400: properties

C72650C74400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

135 GPa19.6 Msi
124 GPa18 Msi

Shear Modulus

51 GPa7.4 Msi
46 GPa6.7 Msi

Bulk Modulus

113 GPa16.4 Msi
130 GPa18.9 Msi

Poisson's Ratio

0.3
0.34

Tensile Strength (Ultimate)

795 MPa115 ksi
515 MPa74.7 ksi

Yield Strength (0.2% offset)

745 MPa108 ksi
440 MPa63.8 ksi

Elongation at Break

8%
12%

Reduction in Area

25%
—

Compressive Strength

760 MPa110 ksi
—

Shear Strength

470 MPa68.2 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
200 MPa29 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
—

Hardness, Brinell

285 HB
138 HB

Hardness, Rockwell B

100 HRB
75 HRB

Hardness, Rockwell C

29 HRC
—

Hardness, Vickers

—
145 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,030°C1,886 °F
1,020°C1,868 °F

Liquidus Temperature

1,100°C2,012 °F
1,065°C1,949 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

250°C482 °F
200°C392 °F

Same in both: Latent Heat of Fusion 200 J/g86 BTU/lb · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

12 % IACS
9.8 % IACS

Electrical Resistivity

1.44×10⁻⁷ Ω·m5.67 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

80 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
20%

Weldability

35 / 100
52 / 100

Formability (cold)

30 / 100
70 / 100

Brazeability / Solderability

60 / 100
85 / 100

Polishability

85 / 100
90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

65 MJ/kg27,945 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

4.2 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

260 L/kg31.2 gal/lb
300 L/kg35.9 gal/lb

Typical Recycled Content

30%
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)

15.3 MN·m/kg
14.3 MN·m/kg

Modulus of Resilience

2,056 kJ/m³
781 kJ/m³

Thermal Diffusivity

14.9 mm²/s
13.7 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 scaleC74400C72650

Manufacturing and finishing

CapabilityC72650C74400
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.

C72650 vs C74400 — frequently asked

Is C72650 stronger than C74400?

Yes. C72650 has a typical yield strength of 745 MPa (108 ksi) against 440 MPa (63.8 ksi) for C74400 — about 69% more. Tensile strength is 795 MPa (115 ksi) vs 515 MPa (74.7 ksi).

Which is cheaper, C72650 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, C72650 or C74400?

C72650. Its machinability rates very good (80/100) against poor (25/100) for C74400; for welding the order is C74400 first (fair, 52/100) then C72650 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C72650 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.