Copper Alloy C65400-H03 vs C65400-H08
Copper Alloy · C65400 temper comparison
C65400-H03 and C65400-H08 are two conditions of the same copper alloy grade, C65400: H03 (three-quarter hard) versus H08 (spring hard). The chemistry is identical, so every difference below comes from the condition. C65400-H08 is the stronger of the two: yield strength 725 MPa (105 ksi) against 570 MPa (82.7 ksi) for C65400-H03, about 27% more; tensile strength follows at 760 MPa (110 ksi) vs 620 MPa (89.9 ksi). In exchange, C65400-H03 is the more ductile: elongation 8% versus 3% for C65400-H08, and C65400-H08 is harder (217 HB vs 180 HB). C65400-H03 runs hotter in service (185°C vs 160°C continuous).
C65400-H03Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C65400-H08Choose it when strength drives the design.
C65400-H03 vs C65400-H08: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 117 GPa17 Msi · Shear Modulus 44 GPa6.4 Msi · Bulk Modulus 118 GPa17.1 Msi · Poisson's Ratio 0.34
Physical
Density and transition temperatures.
Same in both: Density 8.53 g/cm³0.31 lb/in³ · Melting Point (Solidus) 971°C1,780 °F · Liquidus Temperature 1,027°C1,881 °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 377 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 18.4 µm/m·K10.2 µin/in·°F · Latent Heat of Fusion 205 J/g88.1 BTU/lb · Min Service Temperature -200°C-328 °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) -0.26 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 40 / 100 · Brazeability / Solderability 85 / 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) 3.6 kg CO₂/kg · Embodied Water 320 L/kg38.3 gal/lb · Typical Recycled Content 35%
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.
C65400-H03 vs C65400-H08 — frequently asked
Is C65400-H08 stronger than C65400-H03?
Yes. C65400-H08 has a typical yield strength of 725 MPa (105 ksi) against 570 MPa (82.7 ksi) for C65400-H03 — about 27% more. Tensile strength is 760 MPa (110 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, H03 or H08?
H04 is the default C65400 condition in the FabDigit quote flow (neither H03 nor H08). 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.
When should I choose C65400-H03 over C65400-H08?
Pick C65400-H03 when the part is bent, formed or impact-loaded, or when the part sees heat. Pick C65400-H08 when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C65400-H03 and C65400-H08 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.