Copper Alloy C76400-H04 vs C76400-O61
Copper Alloy · C76400 temper comparison
C76400-H04 and C76400-O61 are two conditions of the same copper alloy grade, C76400: H04 (full hard) versus O61 (annealed). The chemistry is identical, so every difference below comes from the condition. C76400-H04 is the stronger of the two: yield strength 510 MPa (74 ksi) against 170 MPa (24.7 ksi) for C76400-O61, about 3.0 times as much; tensile strength follows at 585 MPa (84.8 ksi) vs 390 MPa (56.6 ksi). In exchange, C76400-O61 is the more ductile: elongation 40% versus 4% for C76400-H04, and C76400-H04 is harder (165 HB vs 90 HB). C76400-O61 runs hotter in service (300°C vs 200°C continuous).
C76400-H04Choose it when strength drives the design.
C76400-O61Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C76400-H04 vs C76400-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
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 125 GPa18.1 Msi · Shear Modulus 46 GPa6.7 Msi · Bulk Modulus 130 GPa18.9 Msi · Poisson's Ratio 0.35
Physical
Density and transition temperatures.
Same in both: Density 8.7 g/cm³0.31 lb/in³ · Melting Point (Solidus) 1,040°C1,904 °F · Liquidus Temperature 1,090°C1,994 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 29 W/m·K16.8 BTU/hr·ft·°F · Specific Heat Capacity 377 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.2 µm/m·K9 µin/in·°F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 6 % IACS · Electrical Resistivity 2.9×10⁻⁷ Ω·m11.4 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.22 V · Corrosion Resistance 68 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 25% · Weldability 55 / 100 · Castability 35 / 100 · Brazeability / Solderability 80 / 100 · Polishability 85 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · Embodied Carbon (primary production) 5.5 kg CO₂/kg · Embodied Water 320 L/kg38.3 gal/lb · Typical Recycled Content 40%
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.
C76400-H04 vs C76400-O61 — frequently asked
Is C76400-H04 stronger than C76400-O61?
Yes. C76400-H04 has a typical yield strength of 510 MPa (74 ksi) against 170 MPa (24.7 ksi) for C76400-O61 — about 3.0 times as much. Tensile strength is 585 MPa (84.8 ksi) vs 390 MPa (56.6 ksi).
Which condition does FabDigit quote by default, H04 or O61?
H04 is the default C76400 condition in the FabDigit quote flow. 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, C76400-H04 or C76400-O61?
C76400-H04, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for C76400-O61.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C76400-H04 and C76400-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.