Copper Alloy C21000-H03 vs C21000-H04
Copper Alloy · C21000 temper comparison
C21000-H03 and C21000-H04 are two conditions of the same copper alloy grade, C21000: H03 (three-quarter hard) versus H04 (full hard). The chemistry is identical, so every difference below comes from the condition. C21000-H04 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for C21000-H03, about 13% more; tensile strength follows at 380 MPa (55.1 ksi) vs 345 MPa (50 ksi). In exchange, C21000-H03 is the more ductile: elongation 9% versus 5% for C21000-H04, and C21000-H04 is harder (105 HB vs 95 HB). C21000-H03 runs hotter in service (150°C vs 130°C continuous).
C21000-H03Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C21000-H04Choose it when strength drives the design.
C21000-H03 vs C21000-H04: 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, Vickers
Same in both: Elastic (Young's) Modulus 115 GPa16.7 Msi · Shear Modulus 43 GPa6.2 Msi · Bulk Modulus 128 GPa18.6 Msi · Poisson's Ratio 0.34 · Reduction in Area 70%
Physical
Density and transition temperatures.
Same in both: Density 8.86 g/cm³0.32 lb/in³ · Melting Point (Solidus) 1,055°C1,931 °F · Liquidus Temperature 1,066°C1,951 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 226 W/m·K131 BTU/hr·ft·°F · Specific Heat Capacity 380 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 18.1 µm/m·K10.1 µin/in·°F · Latent Heat of Fusion 205 J/g88.1 BTU/lb · Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 54 % IACS · Electrical Resistivity 3.08×10⁻⁸ Ω·m1.21 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.22 V · Corrosion Resistance 62 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Machinability 22 / 100 · Weldability 60 / 100 · Castability 45 / 100 · Brazeability / Solderability 95 / 100 · Polishability 90 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.8 kg CO₂/kg · Embodied Water 260 L/kg31.2 gal/lb · Typical Recycled Content 45%
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.
C21000-H03 vs C21000-H04 — frequently asked
Is C21000-H04 stronger than C21000-H03?
Yes. C21000-H04 has a typical yield strength of 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for C21000-H03 — about 13% more. Tensile strength is 380 MPa (55.1 ksi) vs 345 MPa (50 ksi).
Which condition does FabDigit quote by default, H03 or H04?
OS050 is the default C21000 condition in the FabDigit quote flow (neither H03 nor H04). 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 C21000-H03 over C21000-H04?
Pick C21000-H03 when the part is bent, formed or impact-loaded, or when the part sees heat. Pick C21000-H04 when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C21000-H03 and C21000-H04 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.