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Copper Alloy C72900 vs C74500

Copper Alloy · grade comparison

Copper Alloy C72900 and C74500 are both copper alloy grades. C72900 is the stronger of the two: yield strength 1,000 MPa (145 ksi) against 400 MPa (58 ksi) for C74500, about 150% more; tensile strength follows at 1,105 MPa (160 ksi) vs 510 MPa (74 ksi). In exchange, C74500 is the more ductile: elongation 12% versus 10% for C72900, and C72900 is harder (330 HB vs 150 HB). C72900 runs hotter in service (250°C vs 180°C continuous) and C74500 conducts heat better (45 W/m·K vs 35 W/m·K). On the shop floor, C72900 machines more easily (good vs poor) and C74500 welds better (fair vs poor).

C72900Choose it when strength drives the design, or when the part sees heat.

C74500Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

C72900 vs C74500: properties

C72900C74500

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

131 GPa19 Msi
127 GPa18.4 Msi

Shear Modulus

50 GPa7.3 Msi
48 GPa7 Msi

Bulk Modulus

109 GPa15.8 Msi
128 GPa18.6 Msi

Poisson's Ratio

0.3
0.33

Tensile Strength (Ultimate)

1,105 MPa160 ksi
510 MPa74 ksi

Yield Strength (0.2% offset)

1,000 MPa145 ksi
400 MPa58 ksi

Elongation at Break

10%
12%

Reduction in Area

20%
—

Compressive Strength

1,020 MPa148 ksi
—

Shear Strength

650 MPa94.3 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
180 MPa26.1 ksi

Hardness, Brinell

330 HB
150 HB

Hardness, Rockwell C

35 HRC
—

Hardness, Vickers

350 HV
158 HV

Hardness, Rockwell B

—
80 HRB

Physical

Density and transition temperatures.

Density

8.86 g/cm³0.32 lb/in³
8.73 g/cm³0.32 lb/in³

Melting Point (Solidus)

1,050°C1,922 °F
954°C1,749 °F

Liquidus Temperature

1,140°C2,084 °F
1,021°C1,870 °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)

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

Max Service Temperature (continuous)

250°C482 °F
180°C356 °F

Latent Heat of Fusion

—
195 J/g83.8 BTU/lb

Same in both: Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.5 % IACS
9 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 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)

-0.25 V
-0.26 V

Corrosion Resistance

78 / 100
62 / 100

Manufacturability

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

Machinability

65 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
20%

Weldability

25 / 100
40 / 100

Formability (cold)

20 / 100
60 / 100

Brazeability / Solderability

55 / 100
88 / 100

Polishability

80 / 100
90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
78 MJ/kg33,534 BTU/lb

Embodied Carbon (primary production)

7 kg CO₂/kg
5.2 kg CO₂/kg

Embodied Water

320 L/kg38.3 gal/lb
260 L/kg31.2 gal/lb

Typical Recycled Content

25%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

125 kN·m/kg
58 kN·m/kg

Specific Stiffness (E / density)

14.8 MN·m/kg
14.5 MN·m/kg

Modulus of Resilience

3,817 kJ/m³
630 kJ/m³

Thermal Diffusivity

10.4 mm²/s
13.7 mm²/s

Thermal Shock Resistance Index

18
11

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 scaleC74500C72900

Manufacturing and finishing

CapabilityC72900C74500
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.

C72900 vs C74500 — frequently asked

Is C72900 stronger than C74500?

Yes. C72900 has a typical yield strength of 1,000 MPa (145 ksi) against 400 MPa (58 ksi) for C74500 — about 150% more. Tensile strength is 1,105 MPa (160 ksi) vs 510 MPa (74 ksi).

Which is cheaper, C72900 or C74500?

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, C72900 or C74500?

C72900. Its machinability rates good (65/100) against poor (30/100) for C74500; for welding the order is C74500 first (fair, 40/100) then C72900 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C72900 and C74500 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.