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Copper Alloy C70400 vs C70600

Copper Alloy · grade comparison

Copper Alloy C70400 and C70600 are both copper alloy grades. C70600 is the stronger of the two: yield strength 120 MPa (17.4 ksi) against 105 MPa (15.2 ksi) for C70400, about 14% more; tensile strength follows at 310 MPa (45 ksi) vs 275 MPa (39.9 ksi). In exchange, C70400 is the more ductile: elongation 46% versus 40% for C70600, and C70400 is harder (70 HB vs 65 HB). C70400 is stiffer (138 GPa vs 124 GPa) and C70400 conducts heat better (65 W/m·K vs 40 W/m·K). On the shop floor, C70600 welds better (excellent vs very good).

C70400Choose it when the part is bent, formed or impact-loaded.

C70600Choose it when strength drives the design, or when it will be welded.

C70400 vs C70600: properties

C70400C70600

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

138 GPa20 Msi
124 GPa18 Msi

Shear Modulus

52 GPa7.5 Msi
47 GPa6.8 Msi

Bulk Modulus

135 GPa19.6 Msi
130 GPa18.9 Msi

Tensile Strength (Ultimate)

275 MPa39.9 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

105 MPa15.2 ksi
120 MPa17.4 ksi

Elongation at Break

46%
40%

Reduction in Area

65%
60%

Shear Strength

195 MPa28.3 ksi
205 MPa29.7 ksi

Fatigue Strength (Endurance Limit)

110 MPa16 ksi
125 MPa18.1 ksi

Hardness, Brinell

70 HB
65 HB

Hardness, Vickers

—
70 HV

Same in both: Poisson's Ratio 0.33 · Hardness, Rockwell B 25 HRB

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,099°C2,010 °F
1,100°C2,012 °F

Liquidus Temperature

1,149°C2,100 °F
1,145°C2,093 °F

Same in both: Density 8.94 g/cm³0.32 lb/in³

Thermal

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

Thermal Conductivity

65 W/m·K37.6 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

16.3 µm/m·K9.1 µin/in·°F
17 µm/m·K9.4 µin/in·°F

Min Service Temperature

-196°C-321 °F
-195°C-319 °F

Same in both: Latent Heat of Fusion 200 J/g86 BTU/lb · Max Service Temperature (continuous) 300°C572 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

13 % IACS
9.5 % IACS

Electrical Resistivity

1.33×10⁻⁷ Ω·m5.24 µΩ·in
1.82×10⁻⁷ Ω·m7.17 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.26 V
-0.28 V

Corrosion Resistance

75 / 100
78 / 100

Manufacturability

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

Machinability

22 / 100
28 / 100

Weldability

80 / 100
92 / 100

Formability (cold)

92 / 100
90 / 100

Castability

40 / 100
45 / 100

Brazeability / Solderability

90 / 100
88 / 100

Polishability

75 / 100
80 / 100

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

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

65 MJ/kg27,945 BTU/lb
75 MJ/kg32,244 BTU/lb

Embodied Carbon (primary production)

4.6 kg CO₂/kg
5.2 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
320 L/kg38.3 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
35 kN·m/kg

Specific Stiffness (E / density)

15.4 MN·m/kg
13.9 MN·m/kg

Modulus of Resilience

40 kJ/m³
58 kJ/m³

Thermal Diffusivity

19.3 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

8
6

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 scaleC70600C70400

Manufacturing and finishing

CapabilityC70400C70600
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.

C70400 vs C70600 — frequently asked

Is C70600 stronger than C70400?

Yes. C70600 has a typical yield strength of 120 MPa (17.4 ksi) against 105 MPa (15.2 ksi) for C70400 — about 14% more. Tensile strength is 310 MPa (45 ksi) vs 275 MPa (39.9 ksi).

Which is cheaper, C70400 or C70600?

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, C70400 or C70600?

C70600, by a small margin. Both rate poor for machinability — 28/100 against 22/100 for C70400; for welding the order is C70600 first (excellent, 92/100) then C70400 (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C70400 and C70600 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.