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Copper Alloy C84400 vs C93900

Copper Alloy · grade comparison

Copper Alloy C84400 and C93900 are both copper alloy grades. C93900 is the stronger of the two: yield strength 152 MPa (22 ksi) against 110 MPa (16 ksi) for C84400, about 38% more. In exchange, C84400 is the more ductile: elongation 26% versus 5% for C93900, and C93900 is harder (70 HB vs 55 HB). C84400 is stiffer (95 GPa vs 76 GPa) and C84400 conducts heat better (72 W/m·K vs 47 W/m·K). On the shop floor, C84400 welds better (poor vs not recommended) and C93900 sits in a lower cost tier (high, $$$$) than C84400 (specialty, $$$$$).

C84400Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

C93900Choose it when strength drives the design, or when cost is the deciding factor.

C84400 vs C93900: properties

C84400C93900

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

95 GPa13.8 Msi
76 GPa11 Msi

Shear Modulus

36 GPa5.2 Msi
28 GPa4.1 Msi

Bulk Modulus

115 GPa16.7 Msi
—

Tensile Strength (Ultimate)

234 MPa33.9 ksi
207 MPa30 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
152 MPa22 ksi

Elongation at Break

26%
5%

Compressive Strength

260 MPa37.7 ksi
172 MPa24.9 ksi

Shear Strength

165 MPa23.9 ksi
152 MPa22 ksi

Fatigue Strength (Endurance Limit)

76 MPa11 ksi
69 MPa10 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

55 HB
70 HB

Hardness, Rockwell B

25 HRB
—

Reduction in Area

—
7%

Hardness, Vickers

—
74 HV

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

843°C1,549 °F
762°C1,404 °F

Liquidus Temperature

954°C1,749 °F
943°C1,729 °F

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
251 J/kg·K0.06 BTU/lb·°F

Latent Heat of Fusion

170 J/g73.1 BTU/lb
150 J/g64.5 BTU/lb

Min Service Temperature

-200°C-328 °F
-100°C-148 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 18 µm/m·K10 µin/in·°F · Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

16.4 % IACS
11.5 % IACS

Electrical Resistivity

1.05×10⁻⁷ Ω·m4.13 µΩ·in
1.5×10⁻⁷ Ω·m5.91 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.31 V

Corrosion Resistance

58 / 100
45 / 100

Manufacturability

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

Machinability

90 / 100
82 / 100

Machinability Rating (AISI 1212 = 100 %)

90%
80%

Weldability

20 / 100
8 / 100

Formability (cold)

10 / 100
5 / 100

Castability

90 / 100
88 / 100

Brazeability / Solderability

80 / 100
35 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
40 MJ/kg17,197 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
2.8 kg CO₂/kg

Typical Recycled Content

85%
70%

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
24 kN·m/kg

Specific Stiffness (E / density)

10.8 MN·m/kg
8.7 MN·m/kg

Modulus of Resilience

64 kJ/m³
152 kJ/m³

Thermal Diffusivity

21.7 mm²/s
21.3 mm²/s

Thermal Shock Resistance Index

10
7

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 scaleC84400C93900

Manufacturing and finishing

CapabilityC84400C93900
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 C93900 — frequently asked

Is C93900 stronger than C84400?

Yes. C93900 has a typical yield strength of 152 MPa (22 ksi) against 110 MPa (16 ksi) for C84400 — about 38% more. Tensile strength is 207 MPa (30 ksi) vs 234 MPa (33.9 ksi).

Which is cheaper, C84400 or C93900?

C93900 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 C93900?

C84400. Its machinability rates excellent (90/100) against very good (82/100) for C93900; for welding the order is C84400 first (poor, 20/100) then C93900 (not recommended, 8/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C84400 and C93900 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.