Copper Alloy C21000 vs C28000
Copper Alloy · grade comparison
Copper Alloy C21000 and C28000 are both copper alloy grades. C28000 is the stronger of the two: yield strength 145 MPa (21 ksi) against 75 MPa (10.9 ksi) for C21000, about 93% more; tensile strength follows at 372 MPa (54 ksi) vs 240 MPa (34.8 ksi). C28000 is harder — 75 HB against 45 HB for C21000 — which matters for wear surfaces and threads. C28000 is lighter (8.39 g/cm³ vs 8.86 g/cm³ for C21000) and C21000 is stiffer (115 GPa vs 105 GPa). On the shop floor, C28000 machines more easily (good vs poor), C21000 welds better (good vs fair), and C21000 forms better (excellent vs good).
C21000Choose it when it will be welded.
C28000Choose it when strength drives the design, or when surface hardness matters.
C21000 vs C28000: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Hardness, Rockwell B
Same in both: Poisson's Ratio 0.34 · Elongation at Break 45%
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Min Service Temperature
Same in both: Max Service Temperature (continuous) 200°C392 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | C21000 | C28000 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | O |
| Relative cost | $$$$ High | $$$ Premium |
| 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.
C21000 vs C28000 — frequently asked
Is C28000 stronger than C21000?
Yes. C28000 has a typical yield strength of 145 MPa (21 ksi) against 75 MPa (10.9 ksi) for C21000 — about 93% more. Tensile strength is 372 MPa (54 ksi) vs 240 MPa (34.8 ksi).
Which is cheaper, C21000 or C28000?
C28000 is the lower-cost material: it sits in the premium tier ($$$) while C21000 is high ($$$$). 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, C21000 or C28000?
C28000. Its machinability rates good (55/100) against poor (22/100) for C21000; for welding the order is C21000 first (good, 60/100) then C28000 (fair, 50/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C21000 and C28000 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.