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Copper Alloy C74500 vs C79800

Copper Alloy · grade comparison

Copper Alloy C74500 and C79800 are both copper alloy grades. Both yield at about 400 MPa — strength does not separate them. C79800 is the more ductile: elongation 15% versus 12% for C74500. C74500 is stiffer (127 GPa vs 117 GPa) and C79800 runs hotter in service (200°C vs 180°C continuous). On the shop floor, C79800 machines more easily (good vs poor) and C74500 welds better (fair vs poor).

C74500Choose it when it will be welded.

C79800Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C74500 vs C79800: properties

C74500C79800

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

127 GPa18.4 Msi
117 GPa17 Msi

Shear Modulus

48 GPa7 Msi
44 GPa6.4 Msi

Bulk Modulus

128 GPa18.6 Msi
115 GPa16.7 Msi

Tensile Strength (Ultimate)

510 MPa74 ksi
525 MPa76.1 ksi

Elongation at Break

12%
15%

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
190 MPa27.6 ksi

Hardness, Brinell

150 HB
155 HB

Hardness, Rockwell B

80 HRB
82 HRB

Hardness, Vickers

158 HV
165 HV

Same in both: Poisson's Ratio 0.33 · Yield Strength (0.2% offset) 400 MPa58 ksi · Shear Strength 330 MPa47.9 ksi

Physical

Density and transition temperatures.

Density

8.73 g/cm³0.32 lb/in³
8.69 g/cm³0.31 lb/in³

Melting Point (Solidus)

954°C1,749 °F
890°C1,634 °F

Liquidus Temperature

1,021°C1,870 °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
16.5 µm/m·K9.2 µin/in·°F

Latent Heat of Fusion

195 J/g83.8 BTU/lb
175 J/g75.2 BTU/lb

Max Service Temperature (continuous)

180°C356 °F
200°C392 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
7 % IACS

Electrical Resistivity

1.92×10⁻⁷ Ω·m7.56 µΩ·in
2.46×10⁻⁷ Ω·m9.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.26 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

30 / 100
68 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
60%

Weldability

40 / 100
15 / 100

Formability (cold)

60 / 100
40 / 100

Brazeability / Solderability

88 / 100
65 / 100

Polishability

90 / 100
85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
72 MJ/kg30,954 BTU/lb

Embodied Carbon (primary production)

5.2 kg CO₂/kg
4.8 kg CO₂/kg

Same in both: Embodied Water 260 L/kg31.2 gal/lb · Typical Recycled Content 40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

58 kN·m/kg
60 kN·m/kg

Specific Stiffness (E / density)

14.5 MN·m/kg
13.5 MN·m/kg

Modulus of Resilience

630 kJ/m³
684 kJ/m³

Thermal Diffusivity

13.7 mm²/s
10 mm²/s

Thermal Shock Resistance Index

11
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 scaleC74500C79800

Manufacturing and finishing

CapabilityC74500C79800
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.

C74500 vs C79800 — frequently asked

What is the difference between C74500 and C79800?

Copper Alloy C74500 and C79800 are both copper alloy grades. Both yield at about 400 MPa — strength does not separate them. C79800 is the more ductile: elongation 15% versus 12% for C74500.

Which is cheaper, C74500 or C79800?

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, C74500 or C79800?

C79800. Its machinability rates good (68/100) against poor (30/100) for C74500; for welding the order is C74500 first (fair, 40/100) then C79800 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C74500 and C79800 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.