Nickel Alloy Inconel 718 vs Inconel 725
Nickel Alloy · grade comparison
Nickel Alloy Inconel 718 and Inconel 725 are both nickel alloy grades. Inconel 725 is the stronger of the two: yield strength 890 MPa (129 ksi) against 550 MPa (79.8 ksi) for Inconel 718, about 62% more; tensile strength follows at 1,240 MPa (180 ksi) vs 965 MPa (140 ksi). In exchange, Inconel 718 is the more ductile: elongation 45% versus 25% for Inconel 725, and Inconel 725 is harder (330 HB vs 200 HB). Inconel 725 runs hotter in service (650°C vs 540°C continuous). On the shop floor, Inconel 718 welds better (very good vs good) and Inconel 718 sits in a lower cost tier (premium, $$$) than Inconel 725 (high, $$$$).
Inconel 718Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
Inconel 725Choose it when strength drives the design, or when the part sees heat.
Inconel 718 vs Inconel 725: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all nickel 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 nickel 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Hardness, Rockwell C
Same in both: Poisson's Ratio 0.29
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
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 435 J/kg·K0.1 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 250 MJ/kg107,481 BTU/lb
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 nickel alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Inconel 718 | Inconel 725 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| 3D printing | Yes | — |
| Default condition | Solution Annealed | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | 1.5 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
They share 3 finishes: Gold Plating, Plasma Spray, Silver Plating.
Inconel 718 vs Inconel 725 — frequently asked
Is Inconel 725 stronger than Inconel 718?
Yes. Inconel 725 has a typical yield strength of 890 MPa (129 ksi) against 550 MPa (79.8 ksi) for Inconel 718 — about 62% more. Tensile strength is 1,240 MPa (180 ksi) vs 965 MPa (140 ksi).
Which is cheaper, Inconel 718 or Inconel 725?
Inconel 718 is the lower-cost material: it sits in the premium tier ($$$) while Inconel 725 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, Inconel 718 or Inconel 725?
Inconel 718. Its weldability rates very good (70/100) against good (55/100) for Inconel 725.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Inconel 718 and Inconel 725 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.