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Copper Alloy C84400 vs CC491K

Copper Alloy · grade comparison

Copper Alloy C84400 and CC491K are both copper alloy grades. CC491K is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 234 MPa (33.9 ksi) for C84400, about 7% more. CC491K is harder — 60 HB against 55 HB for C84400 — which matters for wear surfaces and threads. CC491K is stiffer (100 GPa vs 95 GPa). On the shop floor, CC491K sits in a lower cost tier (high, $$$$) than C84400 (specialty, $$$$$).

CC491KChoose it when strength drives the design, or when surface hardness matters.

C84400 vs CC491K: properties

C84400CC491K

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

95 GPa13.8 Msi
100 GPa14.5 Msi

Shear Modulus

36 GPa5.2 Msi
37 GPa5.4 Msi

Bulk Modulus

115 GPa16.7 Msi
104 GPa15.1 Msi

Tensile Strength (Ultimate)

234 MPa33.9 ksi
250 MPa36.3 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
115 MPa16.7 ksi

Elongation at Break

26%
25%

Compressive Strength

260 MPa37.7 ksi
235 MPa34.1 ksi

Shear Strength

165 MPa23.9 ksi
190 MPa27.6 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

55 HB
60 HB

Hardness, Rockwell B

25 HRB
30 HRB

Reduction in Area

—
25%

Hardness, Vickers

—
63 HV

Same in both: Poisson's Ratio 0.34 · Fatigue Strength (Endurance Limit) 76 MPa11 ksi

Physical

Density and transition temperatures.

Density

8.8 g/cm³0.32 lb/in³
8.83 g/cm³0.32 lb/in³

Melting Point (Solidus)

843°C1,549 °F
854°C1,569 °F

Liquidus Temperature

954°C1,749 °F
1,010°C1,850 °F

Thermal

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

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Same in both: Thermal Conductivity 72 W/m·K41.6 BTU/hr·ft·°F · Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 18 µm/m·K10 µin/in·°F · Latent Heat of Fusion 170 J/g73.1 BTU/lb · Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

16.4 % IACS
15 % IACS

Electrical Resistivity

1.05×10⁻⁷ Ω·m4.13 µΩ·in
1.15×10⁻⁷ Ω·m4.53 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.25 V

Corrosion Resistance

58 / 100
70 / 100

Manufacturability

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

Machinability

90 / 100
85 / 100

Machinability Rating (AISI 1212 = 100 %)

90%
84%

Weldability

20 / 100
25 / 100

Formability (cold)

10 / 100
15 / 100

Brazeability / Solderability

80 / 100
75 / 100

Polishability

60 / 100
65 / 100

Same in both: Castability 90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
52 MJ/kg22,356 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
3.6 kg CO₂/kg

Typical Recycled Content

85%
80%

Same in both: Embodied Water 250 L/kg30 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

27 kN·m/kg
28 kN·m/kg

Specific Stiffness (E / density)

10.8 MN·m/kg
11.3 MN·m/kg

Modulus of Resilience

64 kJ/m³
66 kJ/m³

Thermal Diffusivity

21.7 mm²/s
21.6 mm²/s

Same in both: Thermal Shock Resistance Index 10

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 scaleC84400CC491K

Manufacturing and finishing

CapabilityC84400CC491K
CNC machiningYes—
Default conditionAs Cast—
Relative cost$$$$$ Specialty$$$$ High
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
Chrome PlatingYes—
ElectropolishingYes—
Nickel PlatingYes—
PaintingYes—
Tin PlatingYes—

They share 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.

C84400 vs CC491K — frequently asked

Is CC491K stronger than C84400?

Yes. CC491K has a typical tensile strength of 250 MPa (36.3 ksi) against 234 MPa (33.9 ksi) for C84400 — about 7% more.

Which is cheaper, C84400 or CC491K?

CC491K is the lower-cost material: it sits in the high tier ($$$$) while C84400 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, C84400 or CC491K?

C84400, by a small margin. Both rate excellent for machinability — 90/100 against 85/100 for CC491K; for welding the order is CC491K first (poor, 25/100) then C84400 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84400 and CC491K 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.