FabDigitFabDigit

Copper Alloy C84400 vs C91000

Copper Alloy · grade comparison

Copper Alloy C84400 and C91000 are both copper alloy grades. C91000 is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 110 MPa (16 ksi) for C84400, about 36% more. In exchange, C84400 is the more ductile: elongation 26% versus 1.5% for C91000, and C91000 is harder (135 HB vs 55 HB). C91000 is stiffer (103 GPa vs 95 GPa) and C91000 runs hotter in service (250°C vs 200°C continuous). On the shop floor, C84400 machines more easily (excellent vs poor) and C91000 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.

C91000Choose it when strength drives the design, or when the part sees heat.

C84400 vs C91000: properties

C84400C91000

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
39 GPa5.7 Msi

Poisson's Ratio

0.34
0.33

Tensile Strength (Ultimate)

234 MPa33.9 ksi
225 MPa32.6 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
150 MPa21.8 ksi

Elongation at Break

26%
1.5%

Compressive Strength

260 MPa37.7 ksi
550 MPa79.8 ksi

Shear Strength

165 MPa23.9 ksi
170 MPa24.7 ksi

Fatigue Strength (Endurance Limit)

76 MPa11 ksi
90 MPa13.1 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
3 J2.2 ft·lbf

Hardness, Brinell

55 HB
135 HB

Hardness, Rockwell B

25 HRB
75 HRB

Reduction in Area

—
2%

Hardness, Vickers

—
140 HV

Same in both: Bulk Modulus 115 GPa16.7 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

843°C1,549 °F
830°C1,526 °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
47 W/m·K27.2 BTU/hr·ft·°F

Specific Heat Capacity

377 J/kg·K0.09 BTU/lb·°F
376 J/kg·K0.09 BTU/lb·°F

Latent Heat of Fusion

170 J/g73.1 BTU/lb
175 J/g75.2 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
250°C482 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 18 µm/m·K10 µin/in·°F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

16.4 % IACS
9 % IACS

Electrical Resistivity

1.05×10⁻⁷ Ω·m4.13 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.26 V

Corrosion Resistance

58 / 100
65 / 100

Manufacturability

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

Machinability

90 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

90%
30%

Weldability

20 / 100
15 / 100

Formability (cold)

10 / 100
5 / 100

Castability

90 / 100
70 / 100

Brazeability / Solderability

80 / 100
60 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
4.6 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
300 L/kg35.9 gal/lb

Typical Recycled Content

85%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

27 kN·m/kg
26 kN·m/kg

Specific Stiffness (E / density)

10.8 MN·m/kg
11.7 MN·m/kg

Modulus of Resilience

64 kJ/m³
109 kJ/m³

Thermal Diffusivity

21.7 mm²/s
14.2 mm²/s

Thermal Shock Resistance Index

10
6

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 scaleC84400C91000

Manufacturing and finishing

CapabilityC84400C91000
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 C91000 — frequently asked

Is C91000 stronger than C84400?

Yes. C91000 has a typical yield strength of 150 MPa (21.8 ksi) against 110 MPa (16 ksi) for C84400 — about 36% more. Tensile strength is 225 MPa (32.6 ksi) vs 234 MPa (33.9 ksi).

Which is cheaper, C84400 or C91000?

C91000 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 C91000?

C84400. Its machinability rates excellent (90/100) against poor (30/100) for C91000; for welding the order is C84400 first (poor, 20/100) then C91000 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84400 and C91000 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.