Copper Alloy C51900 vs C61800
Copper Alloy · grade comparison
Copper Alloy C51900 and C61800 are both copper alloy grades. C51900 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 275 MPa (39.9 ksi) for C61800, about 64% more. In exchange, C61800 is the more ductile: elongation 30% versus 20% for C51900, and C61800 is harder (170 HB vs 155 HB). C61800 is lighter (7.58 g/cm³ vs 8.8 g/cm³ for C51900) and C61800 runs hotter in service (300°C vs 200°C continuous). On the shop floor, C61800 welds better (very good vs fair) and C61800 sits in a lower cost tier (high, $$$$) than C51900 (specialty, $$$$$).
C51900Choose it when strength drives the design.
C61800Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
C51900 vs C61800: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Same in both: Reduction in Area 35%
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
Max Service Temperature (continuous)
Same in both: 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
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 40%
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 | C51900 | C61800 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | — | — |
| Relative cost | $$$$$ Specialty | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| Chrome Plating | Yes | — |
| Electropolishing | Yes | — |
| Nickel Plating | Yes | — |
| Painting | Yes | — |
| Tin Plating | Yes | — |
They share 4 finishes: Copper Plating, Electroless Nickel (EN), Gold Plating, Silver Plating.
C51900 vs C61800 — frequently asked
Is C51900 stronger than C61800?
Yes. C51900 has a typical yield strength of 450 MPa (65.3 ksi) against 275 MPa (39.9 ksi) for C61800 — about 64% more. Tensile strength is 520 MPa (75.4 ksi) vs 585 MPa (84.8 ksi).
Which is cheaper, C51900 or C61800?
C61800 is the lower-cost material: it sits in the high tier ($$$$) while C51900 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, C51900 or C61800?
C61800, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for C51900; for welding the order is C61800 first (very good, 70/100) then C51900 (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C51900 and C61800 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.