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Copper Alloy C74400 vs C78200

Copper Alloy · grade comparison

Copper Alloy C74400 and C78200 are both copper alloy grades. C74400 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 407 MPa (59 ksi) for C78200, about 8% more; tensile strength follows at 515 MPa (74.7 ksi) vs 483 MPa (70.1 ksi). C74400 is the more ductile: elongation 12% versus 10% for C78200. C74400 runs hotter in service (200°C vs 150°C continuous) and C74400 conducts heat better (45 W/m·K vs 40 W/m·K). On the shop floor, C78200 machines more easily (good vs poor) and C74400 welds better (fair vs poor).

C74400Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C78200Choose it when the part is machined in volume.

C74400 vs C78200: properties

C74400C78200

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

124 GPa18 Msi
128 GPa18.6 Msi

Shear Modulus

46 GPa6.7 Msi
48 GPa7 Msi

Bulk Modulus

130 GPa18.9 Msi
125 GPa18.1 Msi

Poisson's Ratio

0.34
0.33

Tensile Strength (Ultimate)

515 MPa74.7 ksi
483 MPa70.1 ksi

Yield Strength (0.2% offset)

440 MPa63.8 ksi
407 MPa59 ksi

Elongation at Break

12%
10%

Shear Strength

340 MPa49.3 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
175 MPa25.4 ksi

Hardness, Brinell

138 HB
140 HB

Hardness, Rockwell B

75 HRB
76 HRB

Hardness, Vickers

145 HV
148 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,020°C1,868 °F
966°C1,771 °F

Liquidus Temperature

1,065°C1,949 °F
1,010°C1,850 °F

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

16.2 µm/m·K9 µin/in·°F
16.7 µm/m·K9.3 µin/in·°F

Latent Heat of Fusion

200 J/g86 BTU/lb
175 J/g75.2 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.8 % IACS
9 % IACS

Electrical Resistivity

1.76×10⁻⁷ Ω·m6.93 µΩ·in
1.92×10⁻⁷ Ω·m7.56 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.2 V
-0.24 V

Same in both: Corrosion Resistance 62 / 100

Manufacturability

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

Machinability

25 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
60%

Weldability

52 / 100
20 / 100

Formability (cold)

70 / 100
45 / 100

Brazeability / Solderability

85 / 100
55 / 100

Polishability

90 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

4.5 kg CO₂/kg
5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

59 kN·m/kg
55 kN·m/kg

Specific Stiffness (E / density)

14.3 MN·m/kg
14.7 MN·m/kg

Modulus of Resilience

781 kJ/m³
647 kJ/m³

Thermal Diffusivity

13.7 mm²/s
12.2 mm²/s

Thermal Shock Resistance Index

12
9

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 scaleC74400C78200

Manufacturing and finishing

CapabilityC74400C78200
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.

C74400 vs C78200 — frequently asked

Is C74400 stronger than C78200?

Yes. C74400 has a typical yield strength of 440 MPa (63.8 ksi) against 407 MPa (59 ksi) for C78200 — about 8% more. Tensile strength is 515 MPa (74.7 ksi) vs 483 MPa (70.1 ksi).

Which is cheaper, C74400 or C78200?

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, C74400 or C78200?

C78200. Its machinability rates good (62/100) against poor (25/100) for C74400; for welding the order is C74400 first (fair, 52/100) then C78200 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C74400 and C78200 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.