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Copper Alloy C72800 vs C74400

Copper Alloy · grade comparison

Copper Alloy C72800 and C74400 are both copper alloy grades. C72800 is the stronger of the two: yield strength 800 MPa (116 ksi) against 440 MPa (63.8 ksi) for C74400, about 82% more; tensile strength follows at 930 MPa (135 ksi) vs 515 MPa (74.7 ksi). C72800 is harder — 285 HB against 138 HB for C74400 — which matters for wear surfaces and threads. C72800 is stiffer (135 GPa vs 124 GPa) and C74400 conducts heat better (45 W/m·K vs 35 W/m·K). On the shop floor, C72800 machines more easily (fair vs poor), C74400 welds better (52 vs 40 out of 100), and C74400 forms better (very good vs fair).

C72800Choose it when strength drives the design, or when surface hardness matters.

C74400Choose it when it will be welded.

C72800 vs C74400: properties

C72800C74400

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

115 GPa16.7 Msi
130 GPa18.9 Msi

Poisson's Ratio

0.3
0.34

Tensile Strength (Ultimate)

930 MPa135 ksi
515 MPa74.7 ksi

Yield Strength (0.2% offset)

800 MPa116 ksi
440 MPa63.8 ksi

Reduction in Area

25%
—

Shear Strength

560 MPa81.2 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
200 MPa29 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
—

Hardness, Brinell

285 HB
138 HB

Hardness, Rockwell C

30 HRC
—

Hardness, Vickers

300 HV
145 HV

Hardness, Rockwell B

—
75 HRB

Same in both: Elongation at Break 12%

Physical

Density and transition temperatures.

Density

8.86 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

1,090°C1,994 °F
1,065°C1,949 °F

Thermal

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

Thermal Conductivity

35 W/m·K20.2 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

Latent Heat of Fusion

190 J/g81.7 BTU/lb
200 J/g86 BTU/lb

Same in both: Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
9.8 % IACS

Electrical Resistivity

2.16×10⁻⁷ Ω·m8.5 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

74 / 100
62 / 100

Manufacturability

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

Machinability

35 / 100
25 / 100

Weldability

40 / 100
52 / 100

Formability (cold)

35 / 100
70 / 100

Castability

45 / 100
—

Brazeability / Solderability

65 / 100
85 / 100

Polishability

85 / 100
90 / 100

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

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

72 MJ/kg30,954 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

5.2 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

20%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

105 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

15.2 MN·m/kg
14.3 MN·m/kg

Modulus of Resilience

2,370 kJ/m³
781 kJ/m³

Thermal Diffusivity

10.4 mm²/s
13.7 mm²/s

Thermal Shock Resistance Index

15
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 scaleC74400C72800

Manufacturing and finishing

CapabilityC72800C74400
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.

C72800 vs C74400 — frequently asked

Is C72800 stronger than C74400?

Yes. C72800 has a typical yield strength of 800 MPa (116 ksi) against 440 MPa (63.8 ksi) for C74400 — about 82% more. Tensile strength is 930 MPa (135 ksi) vs 515 MPa (74.7 ksi).

Which is cheaper, C72800 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, C72800 or C74400?

C72800. Its machinability rates fair (35/100) against poor (25/100) for C74400; for welding the order is C74400 first (fair, 52/100) then C72800 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C72800 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.