Copper Alloy C28500-H04 vs C28500-O61
Copper Alloy · C28500 temper comparison
C28500-H04 and C28500-O61 are two conditions of the same copper alloy grade, C28500: H04 (full hard) versus O61 (annealed). The chemistry is identical, so every difference below comes from the condition. C28500-H04 is the stronger of the two: yield strength 410 MPa (59.5 ksi) against 140 MPa (20.3 ksi) for C28500-O61, about 193% more; tensile strength follows at 540 MPa (78.3 ksi) vs 370 MPa (53.7 ksi). In exchange, C28500-O61 is the more ductile: elongation 48% versus 10% for C28500-H04, and C28500-H04 is harder (150 HB vs 65 HB). C28500-O61 runs hotter in service (200°C vs 120°C continuous). On the shop floor, C28500-H04 machines more easily (good vs fair).
C28500-H04Choose it when strength drives the design, or when the part is machined in volume.
C28500-O61Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C28500-H04 vs C28500-O61: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 105 GPa15.2 Msi · Shear Modulus 39 GPa5.7 Msi · Bulk Modulus 111 GPa16.1 Msi · Poisson's Ratio 0.34
Physical
Density and transition temperatures.
Same in both: Density 8.39 g/cm³0.3 lb/in³ · Melting Point (Solidus) 899°C1,650 °F · Liquidus Temperature 904°C1,659 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 375 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 20.8 µm/m·K11.6 µin/in·°F · Latent Heat of Fusion 170 J/g73.1 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.27 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 60 / 100 · Brazeability / Solderability 80 / 100 · Polishability 80 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.3 kg CO₂/kg · Embodied Water 250 L/kg30 gal/lb · Typical Recycled Content 50%
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.
C28500-H04 vs C28500-O61 — frequently asked
Is C28500-H04 stronger than C28500-O61?
Yes. C28500-H04 has a typical yield strength of 410 MPa (59.5 ksi) against 140 MPa (20.3 ksi) for C28500-O61 — about 193% more. Tensile strength is 540 MPa (78.3 ksi) vs 370 MPa (53.7 ksi).
Which condition does FabDigit quote by default, H04 or O61?
M30 is the default C28500 condition in the FabDigit quote flow (neither H04 nor O61). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, C28500-H04 or C28500-O61?
C28500-H04. Its machinability rates good (55/100) against fair (45/100) for C28500-O61; for welding the order is C28500-O61 first (fair, 45/100) then C28500-H04 (fair, 38/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C28500-H04 and C28500-O61 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.