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Copper Alloy C76400-H10 vs C76400-O61

Copper Alloy · C76400 temper comparison

C76400-H10 and C76400-O61 are two conditions of the same copper alloy grade, C76400: H10 (extra spring hard) versus O61 (annealed). The chemistry is identical, so every difference below comes from the condition. C76400-H10 is the stronger of the two: yield strength 670 MPa (97.2 ksi) against 170 MPa (24.7 ksi) for C76400-O61, about 3.9 times as much; tensile strength follows at 750 MPa (109 ksi) vs 390 MPa (56.6 ksi). In exchange, C76400-O61 is the more ductile: elongation 40% versus 2% for C76400-H10, and C76400-H10 is harder (210 HB vs 90 HB). C76400-O61 runs hotter in service (300°C vs 175°C continuous). On the shop floor, C76400-H10 machines more easily (fair vs poor) and C76400-O61 welds better (good vs fair).

C76400-H10Choose it when strength drives the design, or when the part is machined in volume.

C76400-O61Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C76400-H10 vs C76400-O61: properties

C76400-H10C76400-O61

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

127 GPa18.4 Msi
125 GPa18.1 Msi

Tensile Strength (Ultimate)

750 MPa109 ksi
390 MPa56.6 ksi

Yield Strength (0.2% offset)

670 MPa97.2 ksi
170 MPa24.7 ksi

Elongation at Break

2%
40%

Shear Strength

435 MPa63.1 ksi
275 MPa39.9 ksi

Fatigue Strength (Endurance Limit)

225 MPa32.6 ksi
150 MPa21.8 ksi

Hardness, Brinell

210 HB
90 HB

Hardness, Rockwell B

95 HRB
45 HRB

Hardness, Vickers

225 HV
95 HV

Same in both: 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.

Thermal Conductivity

28 W/m·K16.2 BTU/hr·ft·°F
29 W/m·K16.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

175°C347 °F
300°C572 °F

Same in both: 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.

Electrical Conductivity

5.5 % IACS
6 % IACS

Electrical Resistivity

3.1×10⁻⁷ Ω·m12.2 µΩ·in
2.9×10⁻⁷ Ω·m11.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

64 / 100
68 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.22 V

Manufacturability

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

Machinability

35 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
25%

Weldability

45 / 100
55 / 100

Formability (cold)

18 / 100
85 / 100

Same in both: 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.

501002005001,0007.588.599.5Density (g/cm³)Yield strength (MPa) — log scaleC76400

C76400-H10 vs C76400-O61 — frequently asked

Is C76400-H10 stronger than C76400-O61?

Yes. C76400-H10 has a typical yield strength of 670 MPa (97.2 ksi) against 170 MPa (24.7 ksi) for C76400-O61 — about 3.9 times as much. Tensile strength is 750 MPa (109 ksi) vs 390 MPa (56.6 ksi).

Which condition does FabDigit quote by default, H10 or O61?

H04 is the default C76400 condition in the FabDigit quote flow (neither H10 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, C76400-H10 or C76400-O61?

C76400-H10. Its machinability rates fair (35/100) against poor (25/100) for C76400-O61; for welding the order is C76400-O61 first (good, 55/100) then C76400-H10 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C76400-H10 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.