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Copper Alloy C74400 vs C79600

Copper Alloy · grade comparison

Copper Alloy C74400 and C79600 are both copper alloy grades. C74400 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 400 MPa (58 ksi) for C79600, about 10% more. In exchange, C79600 is the more ductile: elongation 15% versus 12% for C74400, and C79600 is harder (160 HB vs 138 HB). C74400 is stiffer (124 GPa vs 117 GPa) and C74400 conducts heat better (45 W/m·K vs 33 W/m·K). On the shop floor, C79600 machines more easily (very good vs poor) and C74400 welds better (fair vs poor).

C74400Choose it when strength drives the design, or when it will be welded.

C79600Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

C74400 vs C79600: properties

C74400C79600

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

124 GPa18 Msi
117 GPa17 Msi

Shear Modulus

46 GPa6.7 Msi
44 GPa6.4 Msi

Bulk Modulus

130 GPa18.9 Msi
115 GPa16.7 Msi

Poisson's Ratio

0.34
0.33

Tensile Strength (Ultimate)

515 MPa74.7 ksi
550 MPa79.8 ksi

Yield Strength (0.2% offset)

440 MPa63.8 ksi
400 MPa58 ksi

Elongation at Break

12%
15%

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
185 MPa26.8 ksi

Hardness, Brinell

138 HB
160 HB

Hardness, Rockwell B

75 HRB
85 HRB

Hardness, Vickers

145 HV
170 HV

Same in both: Shear Strength 340 MPa49.3 ksi

Physical

Density and transition temperatures.

Density

8.7 g/cm³0.31 lb/in³
8.52 g/cm³0.31 lb/in³

Melting Point (Solidus)

1,020°C1,868 °F
875°C1,607 °F

Liquidus Temperature

1,065°C1,949 °F
925°C1,697 °F

Thermal

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

Thermal Conductivity

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

16.2 µm/m·K9 µin/in·°F
18 µm/m·K10 µin/in·°F

Latent Heat of Fusion

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

Min Service Temperature

-200°C-328 °F
-100°C-148 °F

Same in both: Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.8 % IACS
8 % IACS

Electrical Resistivity

1.76×10⁻⁷ Ω·m6.93 µΩ·in
2.15×10⁻⁷ Ω·m8.46 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.2 V
-0.25 V

Corrosion Resistance

62 / 100
55 / 100

Manufacturability

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

Machinability

25 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
70%

Weldability

52 / 100
20 / 100

Formability (cold)

70 / 100
35 / 100

Brazeability / Solderability

85 / 100
70 / 100

Polishability

90 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

4.5 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
40%

Same in both: Embodied Energy (primary production) 62 MJ/kg26,655 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

59 kN·m/kg
65 kN·m/kg

Specific Stiffness (E / density)

14.3 MN·m/kg
13.7 MN·m/kg

Modulus of Resilience

781 kJ/m³
684 kJ/m³

Thermal Diffusivity

13.7 mm²/s
10.2 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 scaleC74400C79600

Manufacturing and finishing

CapabilityC74400C79600
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 C79600 — frequently asked

Is C74400 stronger than C79600?

Yes. C74400 has a typical yield strength of 440 MPa (63.8 ksi) against 400 MPa (58 ksi) for C79600 — about 10% more. Tensile strength is 515 MPa (74.7 ksi) vs 550 MPa (79.8 ksi).

Which is cheaper, C74400 or C79600?

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 C79600?

C79600. Its machinability rates very good (72/100) against poor (25/100) for C74400; for welding the order is C74400 first (fair, 52/100) then C79600 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C74400 and C79600 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.