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Copper Alloy C28000 vs C66300

Copper Alloy · grade comparison

Copper Alloy C28000 and C66300 are both copper alloy grades. C66300 is the stronger of the two: yield strength 600 MPa (87 ksi) against 145 MPa (21 ksi) for C28000, about 4.1 times as much; tensile strength follows at 660 MPa (95.7 ksi) vs 372 MPa (54 ksi). In exchange, C28000 is the more ductile: elongation 45% versus 3.5% for C66300, and C66300 is harder (85 HRB vs 35 HRB). C28000 runs hotter in service (200°C vs 120°C continuous) and C28000 conducts heat better (123 W/m·K vs 105 W/m·K). On the shop floor, C28000 machines more easily (good vs fair), C28000 welds better (fair vs poor), and C28000 sits in a lower cost tier (premium, $$$) than C66300 (high, $$$$).

C28000Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C66300Choose it when strength drives the design.

C28000 vs C66300: properties

C28000C66300

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
110 GPa16 Msi

Shear Modulus

39 GPa5.7 Msi
41 GPa5.9 Msi

Bulk Modulus

112 GPa16.2 Msi
115 GPa16.7 Msi

Tensile Strength (Ultimate)

372 MPa54 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

145 MPa21 ksi
600 MPa87 ksi

Elongation at Break

45%
3.5%

Shear Strength

255 MPa37 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

138 MPa20 ksi
180 MPa26.1 ksi

Hardness, Brinell

75 HB
—

Hardness, Rockwell B

35 HRB
85 HRB

Hardness, Vickers

—
195 HV

Same in both: Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

8.39 g/cm³0.3 lb/in³
8.55 g/cm³0.31 lb/in³

Liquidus Temperature

905°C1,661 °F
935°C1,715 °F

Same in both: Melting Point (Solidus) 900°C1,652 °F

Thermal

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

Thermal Conductivity

123 W/m·K71.1 BTU/hr·ft·°F
105 W/m·K60.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

20.8 µm/m·K11.6 µin/in·°F
19.9 µm/m·K11.1 µin/in·°F

Latent Heat of Fusion

160 J/g68.8 BTU/lb
170 J/g73.1 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
120°C248 °F

Min Service Temperature

-100°C-148 °F
-200°C-328 °F

Same in both: Specific Heat Capacity 375 J/kg·K0.09 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

28 % IACS
25 % IACS

Electrical Resistivity

6.2×10⁻⁸ Ω·m2.44 µΩ·in
6.9×10⁻⁸ Ω·m2.72 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.28 V
-0.25 V

Corrosion Resistance

45 / 100
58 / 100

Manufacturability

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

Machinability

55 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
30%

Weldability

50 / 100
30 / 100

Formability (cold)

55 / 100
20 / 100

Castability

55 / 100
—

Brazeability / Solderability

85 / 100
80 / 100

Polishability

75 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

48 MJ/kg20,636 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

3 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
260 L/kg31.2 gal/lb

Typical Recycled Content

70%
50%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

44 kN·m/kg
77 kN·m/kg

Specific Stiffness (E / density)

12.5 MN·m/kg
12.9 MN·m/kg

Modulus of Resilience

100 kJ/m³
1,636 kJ/m³

Thermal Diffusivity

39.1 mm²/s
32.7 mm²/s

Thermal Shock Resistance Index

21
32

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 scaleC28000C66300

Manufacturing and finishing

CapabilityC28000C66300
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$$ Premium$$$$ 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.

C28000 vs C66300 — frequently asked

Is C66300 stronger than C28000?

Yes. C66300 has a typical yield strength of 600 MPa (87 ksi) against 145 MPa (21 ksi) for C28000 — about 4.1 times as much. Tensile strength is 660 MPa (95.7 ksi) vs 372 MPa (54 ksi).

Which is cheaper, C28000 or C66300?

C28000 is the lower-cost material: it sits in the premium tier ($$$) while C66300 is high ($$$$). 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, C28000 or C66300?

C28000. Its machinability rates good (55/100) against fair (35/100) for C66300; for welding the order is C28000 first (fair, 50/100) then C66300 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C28000 and C66300 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.