Nickel Alloy Inconel 625 vs Inconel 718
Nickel Alloy · grade comparison
Nickel Alloy Inconel 625 and Inconel 718 are both nickel alloy grades. Inconel 718 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 490 MPa (71.1 ksi) for Inconel 625, about 12% more. Inconel 718 is harder — 200 HB against 190 HB for Inconel 625 — which matters for wear surfaces and threads. Inconel 625 runs hotter in service (650°C vs 540°C continuous) and Inconel 718 conducts heat better (11.4 W/m·K vs 9.8 W/m·K). On the shop floor, Inconel 625 welds better (excellent vs very good) and Inconel 625 forms better (very good vs good).
Inconel 625Choose it when the part sees heat, or when it will be welded.
Inconel 718Choose it when strength drives the design, or when surface hardness matters.
Inconel 625 vs Inconel 718: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elongation at Break 45% · Reduction in Area 55% · Fatigue Strength (Endurance Limit) 420 MPa60.9 ksi · Hardness, Rockwell B 92 HRB
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 -253°C-423 °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 Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Machinability 18 / 100 · Castability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 35%
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 625 | Inconel 718 |
|---|---|---|
| Default condition | O | Solution Annealed |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 1.5 mm | 1.5 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining, Sheet metal and 3D printing. Both take the same 5 finishes: Electropolishing, Gold Plating, HVOF Coating, Plasma Spray, Silver Plating.
Inconel 625 vs Inconel 718 — frequently asked
Is Inconel 718 stronger than Inconel 625?
Yes. Inconel 718 has a typical yield strength of 550 MPa (79.8 ksi) against 490 MPa (71.1 ksi) for Inconel 625 — about 12% more. Tensile strength is 965 MPa (140 ksi) vs 930 MPa (135 ksi).
Which is cheaper, Inconel 625 or Inconel 718?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, Inconel 625 or Inconel 718?
Inconel 625. Its weldability rates excellent (88/100) against very good (70/100) for Inconel 718.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Inconel 625 and Inconel 718 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.