FabDigitFabDigit

Copper Alloy C33000 vs C68400

Copper Alloy · grade comparison

Copper Alloy C33000 and C68400 are both copper alloy grades. C68400 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 110 MPa (16 ksi) for C33000, about 3.1 times as much; tensile strength follows at 570 MPa (82.7 ksi) vs 340 MPa (49.3 ksi). In exchange, C33000 is the more ductile: elongation 55% versus 20% for C68400, and C68400 is harder (150 HB vs 55 HB). C33000 conducts heat better (121 W/m·K vs 45 W/m·K). On the shop floor, C33000 machines more easily (very good vs fair) and C68400 welds better (fair vs poor).

C33000Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

C68400Choose it when strength drives the design, or when it will be welded.

C33000 vs C68400: properties

C33000C68400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

111 GPa16.1 Msi
110 GPa16 Msi

Tensile Strength (Ultimate)

340 MPa49.3 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
340 MPa49.3 ksi

Elongation at Break

55%
20%

Reduction in Area

62%
32%

Shear Strength

220 MPa31.9 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

105 MPa15.2 ksi
175 MPa25.4 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

55 HB
150 HB

Hardness, Vickers

58 HV
158 HV

Hardness, Rockwell B

—
80 HRB

Same in both: Elastic (Young's) Modulus 103 GPa14.9 Msi · Shear Modulus 39 GPa5.7 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

8.47 g/cm³0.31 lb/in³
8.35 g/cm³0.3 lb/in³

Melting Point (Solidus)

899°C1,650 °F
865°C1,589 °F

Liquidus Temperature

954°C1,749 °F
890°C1,634 °F

Thermal

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

Thermal Conductivity

121 W/m·K69.9 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Specific Heat Capacity

375 J/kg·K0.09 BTU/lb·°F
380 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

20.2 µm/m·K11.2 µin/in·°F
20.5 µm/m·K11.4 µin/in·°F

Latent Heat of Fusion

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

Same in both: Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
14.5 % IACS

Electrical Resistivity

6.6×10⁻⁸ Ω·m2.6 µΩ·in
1.19×10⁻⁷ Ω·m4.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.27 V

Corrosion Resistance

55 / 100
62 / 100

Manufacturability

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

Machinability

70 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

180%
30%

Weldability

25 / 100
45 / 100

Formability (cold)

85 / 100
45 / 100

Brazeability / Solderability

85 / 100
70 / 100

Polishability

80 / 100
75 / 100

Castability

—
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
50 MJ/kg21,496 BTU/lb

Embodied Carbon (primary production)

3.6 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 50%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

40 kN·m/kg
68 kN·m/kg

Specific Stiffness (E / density)

12.2 MN·m/kg
12.3 MN·m/kg

Modulus of Resilience

59 kJ/m³
561 kJ/m³

Thermal Diffusivity

38.1 mm²/s
14.2 mm²/s

Thermal Shock Resistance Index

20
12

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 scaleC33000C68400

Manufacturing and finishing

CapabilityC33000C68400
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$$$ High$$$$ 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.

C33000 vs C68400 — frequently asked

Is C68400 stronger than C33000?

Yes. C68400 has a typical yield strength of 340 MPa (49.3 ksi) against 110 MPa (16 ksi) for C33000 — about 3.1 times as much. Tensile strength is 570 MPa (82.7 ksi) vs 340 MPa (49.3 ksi).

Which is cheaper, C33000 or C68400?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, C33000 or C68400?

C33000. Its machinability rates very good (70/100) against fair (35/100) for C68400; for welding the order is C68400 first (fair, 45/100) then C33000 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C33000 and C68400 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.