Copper Alloy C74400 vs C79800
Copper Alloy · grade comparison
Copper Alloy C74400 and C79800 are both copper alloy grades. C74400 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 400 MPa (58 ksi) for C79800, about 10% more. In exchange, C79800 is the more ductile: elongation 15% versus 12% for C74400, and C79800 is harder (155 HB vs 138 HB). C74400 is stiffer (124 GPa vs 117 GPa) and C74400 conducts heat better (45 W/m·K vs 33 W/m·K). On the shop floor, C79800 machines more easily (good vs poor) and C74400 welds better (fair vs poor).
C74400Choose it when strength drives the design, or when it will be welded.
C79800Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
C74400 vs C79800: 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | C74400 | C79800 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
C74400 vs C79800 — frequently asked
Is C74400 stronger than C79800?
Yes. C74400 has a typical yield strength of 440 MPa (63.8 ksi) against 400 MPa (58 ksi) for C79800 — about 10% more. Tensile strength is 515 MPa (74.7 ksi) vs 525 MPa (76.1 ksi).
Which is cheaper, C74400 or C79800?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, C74400 or C79800?
C79800. Its machinability rates good (68/100) against poor (25/100) for C74400; for welding the order is C74400 first (fair, 52/100) then C79800 (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C74400 and C79800 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.