Copper Alloy C18700-H04 vs C18700-H08
Copper Alloy · C18700 temper comparison
C18700-H04 and C18700-H08 are two conditions of the same copper alloy grade, C18700: H04 (full hard) versus H08 (spring hard). The chemistry is identical, so every difference below comes from the condition. C18700-H08 is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 275 MPa (39.9 ksi) for C18700-H04, about 24% more; tensile strength follows at 380 MPa (55.1 ksi) vs 315 MPa (45.7 ksi). In exchange, C18700-H04 is the more ductile: elongation 15% versus 5% for C18700-H08, and C18700-H08 is harder (100 HB vs 90 HB). C18700-H04 runs hotter in service (180°C vs 150°C continuous).
C18700-H04Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C18700-H08Choose it when strength drives the design.
C18700-H04 vs C18700-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
Reduction in Area
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 140 GPa20.3 Msi · Poisson's Ratio 0.34
Physical
Density and transition temperatures.
Same in both: Density 8.94 g/cm³0.32 lb/in³ · Melting Point (Solidus) 1,075°C1,967 °F · Liquidus Temperature 1,083°C1,981 °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 385 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 17.7 µm/m·K9.8 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.25 V · Corrosion Resistance 64 / 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 90 / 100 · Weldability 15 / 100 · Brazeability / Solderability 55 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 57 MJ/kg24,506 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 250 L/kg30 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.
C18700-H04 vs C18700-H08 — frequently asked
Is C18700-H08 stronger than C18700-H04?
Yes. C18700-H08 has a typical yield strength of 340 MPa (49.3 ksi) against 275 MPa (39.9 ksi) for C18700-H04 — about 24% more. Tensile strength is 380 MPa (55.1 ksi) vs 315 MPa (45.7 ksi).
Which condition does FabDigit quote by default, H04 or H08?
H04 is the default C18700 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.
When should I choose C18700-H04 over C18700-H08?
Pick C18700-H04 when the part is bent, formed or impact-loaded, or when the part sees heat. Pick C18700-H08 when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C18700-H04 and C18700-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.