FabDigitFabDigit

Copper Alloy C73500 vs C74400

Copper Alloy · grade comparison

Copper Alloy C73500 and C74400 are both copper alloy grades. C74400 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 415 MPa (60.2 ksi) for C73500, about 6% more; tensile strength follows at 515 MPa (74.7 ksi) vs 480 MPa (69.6 ksi). C74400 is the more ductile: elongation 12% versus 10% for C73500, and C74400 is harder (138 HB vs 130 HB). C74400 runs hotter in service (200°C vs 175°C continuous) and C74400 conducts heat better (45 W/m·K vs 33 W/m·K).

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

C73500 vs C74400: properties

C73500C74400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

127 GPa18.4 Msi
124 GPa18 Msi

Shear Modulus

47 GPa6.8 Msi
46 GPa6.7 Msi

Bulk Modulus

128 GPa18.6 Msi
130 GPa18.9 Msi

Tensile Strength (Ultimate)

480 MPa69.6 ksi
515 MPa74.7 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
440 MPa63.8 ksi

Elongation at Break

10%
12%

Shear Strength

330 MPa47.9 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

210 MPa30.5 ksi
200 MPa29 ksi

Hardness, Brinell

130 HB
138 HB

Hardness, Rockwell B

72 HRB
75 HRB

Hardness, Vickers

140 HV
145 HV

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,080°C1,976 °F
1,020°C1,868 °F

Liquidus Temperature

1,110°C2,030 °F
1,065°C1,949 °F

Thermal

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

Thermal Conductivity

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

Latent Heat of Fusion

210 J/g90.3 BTU/lb
200 J/g86 BTU/lb

Max Service Temperature (continuous)

175°C347 °F
200°C392 °F

Same in both: Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.2 µm/m·K9 µin/in·°F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6.2 % IACS
9.8 % IACS

Electrical Resistivity

2.78×10⁻⁷ Ω·m10.9 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

Same in both: Corrosion Resistance 62 / 100

Manufacturability

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

Machinability

30 / 100
25 / 100

Weldability

55 / 100
52 / 100

Formability (cold)

55 / 100
70 / 100

Castability

40 / 100
—

Same in both: Machinability Rating (AISI 1212 = 100 %) 20% · Brazeability / Solderability 85 / 100 · Polishability 90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

5.6 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

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

Same in both: Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
59 kN·m/kg

Modulus of Resilience

678 kJ/m³
781 kJ/m³

Thermal Diffusivity

9.9 mm²/s
13.7 mm²/s

Thermal Shock Resistance Index

8
12

Same in both: Specific Stiffness (E / density) 14.3 MN·m/kg

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 scaleC74400C73500

Manufacturing and finishing

CapabilityC73500C74400
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.

C73500 vs C74400 — frequently asked

Is C74400 stronger than C73500?

Yes. C74400 has a typical yield strength of 440 MPa (63.8 ksi) against 415 MPa (60.2 ksi) for C73500 — about 6% more. Tensile strength is 515 MPa (74.7 ksi) vs 480 MPa (69.6 ksi).

Which is cheaper, C73500 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, C73500 or C74400?

C73500, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for C74400.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C73500 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.