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Copper Alloy C33000 vs C68700

Copper Alloy · grade comparison

Copper Alloy C33000 and C68700 are both copper alloy grades. C68700 is the stronger of the two: yield strength 186 MPa (27 ksi) against 110 MPa (16 ksi) for C33000, about 69% more; tensile strength follows at 415 MPa (60.2 ksi) vs 340 MPa (49.3 ksi). C68700 is harder — 85 HB against 55 HB for C33000 — which matters for wear surfaces and threads. C33000 conducts heat better (121 W/m·K vs 100 W/m·K). On the shop floor, C33000 machines more easily (very good vs poor) and C68700 welds better (fair vs poor).

C33000Choose it when the part is machined in volume.

C68700Choose it when strength drives the design, or when surface hardness matters.

C33000 vs C68700: properties

C33000C68700

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

111 GPa16.1 Msi
105 GPa15.2 Msi

Poisson's Ratio

0.34
0.33

Tensile Strength (Ultimate)

340 MPa49.3 ksi
415 MPa60.2 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
186 MPa27 ksi

Reduction in Area

62%
—

Shear Strength

220 MPa31.9 ksi
275 MPa39.9 ksi

Fatigue Strength (Endurance Limit)

105 MPa15.2 ksi
140 MPa20.3 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
—

Hardness, Brinell

55 HB
85 HB

Hardness, Vickers

58 HV
90 HV

Hardness, Rockwell B

—
52 HRB

Same in both: Elastic (Young's) Modulus 103 GPa14.9 Msi · Shear Modulus 39 GPa5.7 Msi · Elongation at Break 55%

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

899°C1,650 °F
971°C1,780 °F

Liquidus Temperature

954°C1,749 °F
1,027°C1,881 °F

Thermal

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

Thermal Conductivity

121 W/m·K69.9 BTU/hr·ft·°F
100 W/m·K57.8 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

20.2 µm/m·K11.2 µin/in·°F
18 µm/m·K10 µin/in·°F

Latent Heat of Fusion

170 J/g73.1 BTU/lb
200 J/g86 BTU/lb

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Same in both: Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
23 % IACS

Electrical Resistivity

6.6×10⁻⁸ Ω·m2.6 µΩ·in
7.5×10⁻⁸ Ω·m2.95 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.25 V
-0.3 V

Corrosion Resistance

55 / 100
72 / 100

Manufacturability

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

Machinability

70 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

180%
60%

Weldability

25 / 100
35 / 100

Polishability

80 / 100
70 / 100

Same in both: Formability (cold) 85 / 100 · Brazeability / Solderability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
52 MJ/kg22,356 BTU/lb

Embodied Water

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

Typical Recycled Content

50%
30%

Same in both: Embodied Carbon (primary production) 3.6 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

40 kN·m/kg
50 kN·m/kg

Specific Stiffness (E / density)

12.2 MN·m/kg
12.4 MN·m/kg

Modulus of Resilience

59 kJ/m³
168 kJ/m³

Thermal Diffusivity

38.1 mm²/s
31.8 mm²/s

Thermal Shock Resistance Index

20
22

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 scaleC33000C68700

Manufacturing and finishing

CapabilityC33000C68700
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 C68700 — frequently asked

Is C68700 stronger than C33000?

Yes. C68700 has a typical yield strength of 186 MPa (27 ksi) against 110 MPa (16 ksi) for C33000 — about 69% more. Tensile strength is 415 MPa (60.2 ksi) vs 340 MPa (49.3 ksi).

Which is cheaper, C33000 or C68700?

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 C68700?

C33000. Its machinability rates very good (70/100) against poor (30/100) for C68700; for welding the order is C68700 first (fair, 35/100) then C33000 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C33000 and C68700 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.