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Copper Alloy C84400 vs C86400

Copper Alloy · grade comparison

Copper Alloy C84400 and C86400 are both copper alloy grades. C86400 is the stronger of the two: yield strength 193 MPa (28 ksi) against 110 MPa (16 ksi) for C84400, about 75% more; tensile strength follows at 448 MPa (65 ksi) vs 234 MPa (33.9 ksi). In exchange, C84400 is the more ductile: elongation 26% versus 20% for C86400, and C86400 is harder (90 HB vs 55 HB). C86400 is lighter (8.3 g/cm³ vs 8.8 g/cm³ for C84400) and C86400 is stiffer (100 GPa vs 95 GPa). On the shop floor, C84400 machines more easily (excellent vs good), C86400 welds better (30 vs 20 out of 100), and C86400 sits in a lower cost tier (high, $$$$) than C84400 (specialty, $$$$$).

C84400Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

C86400Choose it when strength drives the design, or when weight is the constraint.

C84400 vs C86400: properties

C84400C86400

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
38 GPa5.5 Msi

Bulk Modulus

115 GPa16.7 Msi
105 GPa15.2 Msi

Tensile Strength (Ultimate)

234 MPa33.9 ksi
448 MPa65 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
193 MPa28 ksi

Elongation at Break

26%
20%

Compressive Strength

260 MPa37.7 ksi
205 MPa29.7 ksi

Shear Strength

165 MPa23.9 ksi
310 MPa45 ksi

Fatigue Strength (Endurance Limit)

76 MPa11 ksi
130 MPa18.9 ksi

Hardness, Brinell

55 HB
90 HB

Hardness, Rockwell B

25 HRB
55 HRB

Hardness, Vickers

—
95 HV

Same in both: Poisson's Ratio 0.34 · Charpy V-Notch Impact (RT) 20 J14.8 ft·lbf

Physical

Density and transition temperatures.

Density

8.8 g/cm³0.32 lb/in³
8.3 g/cm³0.3 lb/in³

Melting Point (Solidus)

843°C1,549 °F
862°C1,584 °F

Liquidus Temperature

954°C1,749 °F
880°C1,616 °F

Thermal

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

Thermal Conductivity

72 W/m·K41.6 BTU/hr·ft·°F
87 W/m·K50.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

18 µm/m·K10 µin/in·°F
21.6 µm/m·K12 µin/in·°F

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°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
20 % IACS

Electrical Resistivity

1.05×10⁻⁷ Ω·m4.13 µΩ·in
8.6×10⁻⁸ Ω·m3.39 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.3 V

Corrosion Resistance

58 / 100
52 / 100

Manufacturability

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

Machinability

90 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

90%
65%

Weldability

20 / 100
30 / 100

Formability (cold)

10 / 100
15 / 100

Castability

90 / 100
80 / 100

Brazeability / Solderability

80 / 100
70 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
47 MJ/kg20,206 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
2.9 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

85%
80%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

27 kN·m/kg
54 kN·m/kg

Specific Stiffness (E / density)

10.8 MN·m/kg
12 MN·m/kg

Modulus of Resilience

64 kJ/m³
186 kJ/m³

Thermal Diffusivity

21.7 mm²/s
27.8 mm²/s

Thermal Shock Resistance Index

10
18

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 scaleC84400C86400

Manufacturing and finishing

CapabilityC84400C86400
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 C86400 — frequently asked

Is C86400 stronger than C84400?

Yes. C86400 has a typical yield strength of 193 MPa (28 ksi) against 110 MPa (16 ksi) for C84400 — about 75% more. Tensile strength is 448 MPa (65 ksi) vs 234 MPa (33.9 ksi).

Which is cheaper, C84400 or C86400?

C86400 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 C86400?

C84400. Its machinability rates excellent (90/100) against good (65/100) for C86400; for welding the order is C86400 first (poor, 30/100) then C84400 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84400 and C86400 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.