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Copper Alloy C84800 vs C90900

Copper Alloy · grade comparison

Copper Alloy C84800 and C90900 are both copper alloy grades. C90900 is the stronger of the two: yield strength 152 MPa (22 ksi) against 124 MPa (18 ksi) for C84800, about 23% more. In exchange, C84800 is the more ductile: elongation 35% versus 5% for C90900, and C90900 is harder (80 HB vs 55 HB). C90900 is stiffer (103 GPa vs 86 GPa) and C90900 runs hotter in service (260°C vs 200°C continuous). On the shop floor, C84800 machines more easily (excellent vs poor) and C90900 sits in a lower cost tier (high, $$$$) than C84800 (specialty, $$$$$).

C84800Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

C90900Choose it when strength drives the design, or when the part sees heat.

C84800 vs C90900: properties

C84800C90900

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

86 GPa12.5 Msi
103 GPa14.9 Msi

Shear Modulus

32 GPa4.6 Msi
38 GPa5.5 Msi

Bulk Modulus

105 GPa15.2 Msi
108 GPa15.7 Msi

Tensile Strength (Ultimate)

262 MPa38 ksi
275 MPa39.9 ksi

Yield Strength (0.2% offset)

124 MPa18 ksi
152 MPa22 ksi

Elongation at Break

35%
5%

Shear Strength

190 MPa27.6 ksi
200 MPa29 ksi

Fatigue Strength (Endurance Limit)

76 MPa11 ksi
100 MPa14.5 ksi

Hardness, Brinell

55 HB
80 HB

Reduction in Area

—
6%

Compressive Strength

—
480 MPa69.6 ksi

Charpy V-Notch Impact (RT)

—
7 J5.2 ft·lbf

Hardness, Rockwell B

—
42 HRB

Hardness, Vickers

—
85 HV

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

8.55 g/cm³0.31 lb/in³
8.79 g/cm³0.32 lb/in³

Melting Point (Solidus)

843°C1,549 °F
830°C1,526 °F

Liquidus Temperature

1,010°C1,850 °F
998°C1,828 °F

Thermal

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

Thermal Conductivity

72 W/m·K41.6 BTU/hr·ft·°F
71 W/m·K41 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

18 µm/m·K10 µin/in·°F
18.4 µm/m·K10.2 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
260°C500 °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 · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

16 % IACS
10.5 % IACS

Electrical Resistivity

1.08×10⁻⁷ Ω·m4.25 µΩ·in
1.64×10⁻⁷ Ω·m6.46 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.31 V

Corrosion Resistance

58 / 100
62 / 100

Manufacturability

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

Machinability

88 / 100
32 / 100

Weldability

20 / 100
22 / 100

Castability

90 / 100
72 / 100

Brazeability / Solderability

60 / 100
75 / 100

Polishability

55 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

—
30%

Formability (cold)

—
5 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

45 MJ/kg19,347 BTU/lb
85 MJ/kg36,543 BTU/lb

Embodied Carbon (primary production)

3 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

85%
65%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

10.1 MN·m/kg
11.7 MN·m/kg

Modulus of Resilience

89 kJ/m³
112 kJ/m³

Thermal Diffusivity

22.3 mm²/s
21.4 mm²/s

Thermal Shock Resistance Index

12
10

Same in both: Specific Strength (UTS / density) 31 kN·m/kg

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 scaleC84800C90900

Manufacturing and finishing

CapabilityC84800C90900
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.

C84800 vs C90900 — frequently asked

Is C90900 stronger than C84800?

Yes. C90900 has a typical yield strength of 152 MPa (22 ksi) against 124 MPa (18 ksi) for C84800 — about 23% more. Tensile strength is 275 MPa (39.9 ksi) vs 262 MPa (38 ksi).

Which is cheaper, C84800 or C90900?

C90900 is the lower-cost material: it sits in the high tier ($$$$) while C84800 is specialty ($$$$$). 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, C84800 or C90900?

C84800. Its machinability rates excellent (88/100) against poor (32/100) for C90900.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84800 and C90900 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.