Nickel Alloy Inconel 718 vs Stainless Steel 17-4 PH
Cross-family material comparison
Nickel Alloy Inconel 718 is a nickel alloy grade and Stainless Steel 17-4 PH is a stainless steel grade — different families, so density, stiffness and cost move together with strength. 17-4 PH is the stronger of the two: yield strength 760 MPa (110 ksi) against 550 MPa (79.8 ksi) for Inconel 718, about 38% more; tensile strength follows at 1,030 MPa (149 ksi) vs 965 MPa (140 ksi). In exchange, Inconel 718 is the more ductile: elongation 45% versus 12% for 17-4 PH, and 17-4 PH is harder (311 HB vs 200 HB). 17-4 PH is lighter (7.78 g/cm³ vs 8.19 g/cm³ for Inconel 718) and Inconel 718 runs hotter in service (540°C vs 200°C continuous). On the shop floor, 17-4 PH machines more easily (fair vs poor).
Inconel 718Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
17-4 PHChoose it when strength drives the design, or when weight is the constraint.
Inconel 718 vs 17-4 PH: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all grades of the two families 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 grades of the two families 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
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
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)
Min Service Temperature
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 %)
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Same in both: Weldability 70 / 100
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 grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | Inconel 718 | 17-4 PH |
|---|---|---|
| Casting & forging | — | Yes |
| Default condition | Solution Annealed | Condition A |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 1.5 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| Black Oxide | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| Electroless Nickel (EN) | — | Yes |
| Electropolished (Metal AM) | — | Yes |
| Epoxy Coating | — | Yes |
| Hard Chrome Plating | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
Both are offered for CNC machining, Sheet metal and 3D printing. They share 5 finishes: Electropolishing, Gold Plating, HVOF Coating, Plasma Spray, Silver Plating.
Inconel 718 vs 17-4 PH — frequently asked
Is 17-4 PH stronger than Inconel 718?
Yes. 17-4 PH has a typical yield strength of 760 MPa (110 ksi) against 550 MPa (79.8 ksi) for Inconel 718 — about 38% more. Tensile strength is 1,030 MPa (149 ksi) vs 965 MPa (140 ksi).
Which is cheaper, Inconel 718 or 17-4 PH?
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 is easier to machine, Inconel 718 or 17-4 PH?
17-4 PH. Its machinability rates fair (45/100) against poor (18/100) for Inconel 718.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Inconel 718 and 17-4 PH 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.