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Copper Alloy C28500 vs C33000

Copper Alloy · grade comparison

Copper Alloy C28500 and C33000 are both copper alloy grades. C28500 is the stronger of the two: yield strength 145 MPa (21 ksi) against 110 MPa (16 ksi) for C33000, about 32% more; tensile strength follows at 380 MPa (55.1 ksi) vs 340 MPa (49.3 ksi). In exchange, C33000 is the more ductile: elongation 55% versus 45% for C28500, and C28500 is harder (70 HB vs 55 HB). On the shop floor, C33000 machines more easily (very good vs fair) and C28500 welds better (fair vs poor).

C28500Choose it when strength drives the design, or when it will be welded.

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

C28500 vs C33000: properties

C28500C33000

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
103 GPa14.9 Msi

Tensile Strength (Ultimate)

380 MPa55.1 ksi
340 MPa49.3 ksi

Yield Strength (0.2% offset)

145 MPa21 ksi
110 MPa16 ksi

Elongation at Break

45%
55%

Reduction in Area

52%
62%

Shear Strength

260 MPa37.7 ksi
220 MPa31.9 ksi

Fatigue Strength (Endurance Limit)

125 MPa18.1 ksi
105 MPa15.2 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

70 HB
55 HB

Hardness, Rockwell B

35 HRB
—

Hardness, Vickers

74 HV
58 HV

Same in both: Shear Modulus 39 GPa5.7 Msi · Bulk Modulus 111 GPa16.1 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Density

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

Liquidus Temperature

904°C1,659 °F
954°C1,749 °F

Same in both: Melting Point (Solidus) 899°C1,650 °F

Thermal

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

Thermal Conductivity

123 W/m·K71.1 BTU/hr·ft·°F
121 W/m·K69.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

20.8 µm/m·K11.6 µin/in·°F
20.2 µm/m·K11.2 µin/in·°F

Min Service Temperature

-196°C-321 °F
-200°C-328 °F

Same in both: Specific Heat Capacity 375 J/kg·K0.09 BTU/lb·°F · Latent Heat of Fusion 170 J/g73.1 BTU/lb · Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

28 % IACS
26 % IACS

Electrical Resistivity

6.2×10⁻⁸ Ω·m2.44 µΩ·in
6.6×10⁻⁸ Ω·m2.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.27 V
-0.25 V

Corrosion Resistance

45 / 100
55 / 100

Manufacturability

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

Machinability

45 / 100
70 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
180%

Weldability

45 / 100
25 / 100

Formability (cold)

35 / 100
85 / 100

Castability

60 / 100
—

Brazeability / Solderability

80 / 100
85 / 100

Same in both: Polishability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

3.3 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
180 L/kg21.6 gal/lb

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Typical Recycled Content 50%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

45 kN·m/kg
40 kN·m/kg

Specific Stiffness (E / density)

12.5 MN·m/kg
12.2 MN·m/kg

Modulus of Resilience

100 kJ/m³
59 kJ/m³

Thermal Diffusivity

39.1 mm²/s
38.1 mm²/s

Thermal Shock Resistance Index

21
20

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 scaleC33000C28500

Manufacturing and finishing

CapabilityC28500C33000
CNC machining—Yes
Sheet metal—Yes
Default condition—O
Relative cost$$$$ High$$$$ High
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
Chrome Plating—Yes
Electropolishing—Yes
Nickel Plating—Yes
Painting—Yes
Tin Plating—Yes

They share 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.

C28500 vs C33000 — frequently asked

Is C28500 stronger than C33000?

Yes. C28500 has a typical yield strength of 145 MPa (21 ksi) against 110 MPa (16 ksi) for C33000 — about 32% more. Tensile strength is 380 MPa (55.1 ksi) vs 340 MPa (49.3 ksi).

Which is cheaper, C28500 or C33000?

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, C28500 or C33000?

C33000. Its machinability rates very good (70/100) against fair (45/100) for C28500; for welding the order is C28500 first (fair, 45/100) then C33000 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C28500 and C33000 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.