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Copper Alloy C84400 vs C90300

Copper Alloy · grade comparison

Copper Alloy C84400 and C90300 are both copper alloy grades. C90300 is the stronger of the two: yield strength 145 MPa (21 ksi) against 110 MPa (16 ksi) for C84400, about 32% more; tensile strength follows at 310 MPa (45 ksi) vs 234 MPa (33.9 ksi). C90300 is the more ductile: elongation 30% versus 26% for C84400, and C90300 is harder (70 HB vs 55 HB). C90300 is stiffer (103 GPa vs 95 GPa) and C90300 runs hotter in service (260°C vs 200°C continuous). On the shop floor, C84400 machines more easily (excellent vs good), C90300 welds better (fair vs poor), and C90300 sits in a lower cost tier (high, $$$$) than C84400 (specialty, $$$$$).

C84400Choose it when the part is machined in volume.

C90300Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C84400 vs C90300: properties

C84400C90300

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

95 GPa13.8 Msi
103 GPa14.9 Msi

Shear Modulus

36 GPa5.2 Msi
38 GPa5.5 Msi

Bulk Modulus

115 GPa16.7 Msi
108 GPa15.7 Msi

Tensile Strength (Ultimate)

234 MPa33.9 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
145 MPa21 ksi

Elongation at Break

26%
30%

Compressive Strength

260 MPa37.7 ksi
415 MPa60.2 ksi

Shear Strength

165 MPa23.9 ksi
220 MPa31.9 ksi

Fatigue Strength (Endurance Limit)

76 MPa11 ksi
110 MPa16 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

55 HB
70 HB

Hardness, Rockwell B

25 HRB
—

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Melting Point (Solidus)

843°C1,549 °F
854°C1,569 °F

Liquidus Temperature

954°C1,749 °F
1,000°C1,832 °F

Same in both: Density 8.8 g/cm³0.32 lb/in³

Thermal

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

Thermal Conductivity

72 W/m·K41.6 BTU/hr·ft·°F
75 W/m·K43.3 BTU/hr·ft·°F

Latent Heat of Fusion

170 J/g73.1 BTU/lb
190 J/g81.7 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
260°C500 °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 · Thermal Expansion (CTE, 20–100 °C) 18 µm/m·K10 µin/in·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

16.4 % IACS
12 % IACS

Electrical Resistivity

1.05×10⁻⁷ Ω·m4.13 µΩ·in
1.44×10⁻⁷ Ω·m5.67 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
66 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.28 V

Manufacturability

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

Machinability

90 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

90%
—

Weldability

20 / 100
35 / 100

Formability (cold)

10 / 100
15 / 100

Castability

90 / 100
85 / 100

Brazeability / Solderability

80 / 100
82 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
260 L/kg31.2 gal/lb

Typical Recycled Content

85%
75%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

27 kN·m/kg
35 kN·m/kg

Specific Stiffness (E / density)

10.8 MN·m/kg
11.7 MN·m/kg

Modulus of Resilience

64 kJ/m³
102 kJ/m³

Thermal Diffusivity

21.7 mm²/s
22.6 mm²/s

Thermal Shock Resistance Index

10
13

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 scaleC84400C90300

Manufacturing and finishing

CapabilityC84400C90300
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 C90300 — frequently asked

Is C90300 stronger than C84400?

Yes. C90300 has a typical yield strength of 145 MPa (21 ksi) against 110 MPa (16 ksi) for C84400 — about 32% more. Tensile strength is 310 MPa (45 ksi) vs 234 MPa (33.9 ksi).

Which is cheaper, C84400 or C90300?

C90300 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 C90300?

C84400. Its machinability rates excellent (90/100) against good (55/100) for C90300; for welding the order is C90300 first (fair, 35/100) then C84400 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84400 and C90300 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.