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Nickel Alloy Inconel 718 vs X-750

Nickel Alloy · grade comparison

Nickel Alloy Inconel 718 and X-750 are both nickel alloy grades. X-750 is the stronger of the two: yield strength 815 MPa (118 ksi) against 550 MPa (79.8 ksi) for Inconel 718, about 48% more; tensile strength follows at 1,200 MPa (174 ksi) vs 965 MPa (140 ksi). In exchange, Inconel 718 is the more ductile: elongation 45% versus 24% for X-750, and X-750 is harder (302 HB vs 200 HB). X-750 is stiffer (214 GPa vs 200 GPa) and X-750 runs hotter in service (760°C vs 540°C continuous). On the shop floor, Inconel 718 welds better (very good vs fair) and Inconel 718 sits in a lower cost tier (premium, $$$) than X-750 (high, $$$$).

Inconel 718Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

X-750Choose it when strength drives the design, or when the part sees heat.

Inconel 718 vs X-750: properties

Inconel 718X-750

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
214 GPa31 Msi

Shear Modulus

78 GPa11.3 Msi
83 GPa12 Msi

Bulk Modulus

163 GPa23.6 Msi
188 GPa27.3 Msi

Poisson's Ratio

0.29
0.31

Tensile Strength (Ultimate)

965 MPa140 ksi
1,200 MPa174 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
815 MPa118 ksi

Elongation at Break

45%
24%

Reduction in Area

55%
35%

Shear Strength

620 MPa89.9 ksi
730 MPa106 ksi

Fatigue Strength (Endurance Limit)

420 MPa60.9 ksi
450 MPa65.3 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

130 J95.9 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

200 HB
302 HB

Hardness, Rockwell B

92 HRB
—

Hardness, Vickers

210 HV
320 HV

Compressive Strength

—
840 MPa122 ksi

Hardness, Rockwell C

—
32 HRC

Physical

Density and transition temperatures.

Density

8.19 g/cm³0.3 lb/in³
8.28 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,260°C2,300 °F
1,393°C2,539 °F

Liquidus Temperature

1,336°C2,437 °F
1,427°C2,601 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

11.4 W/m·K6.6 BTU/hr·ft·°F
12 W/m·K6.9 BTU/hr·ft·°F

Specific Heat Capacity

435 J/kg·K0.1 BTU/lb·°F
431 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

13 µm/m·K7.2 µin/in·°F
12.6 µm/m·K7 µin/in·°F

Latent Heat of Fusion

210 J/g90.3 BTU/lb
290 J/g125 BTU/lb

Max Service Temperature (continuous)

540°C1,004 °F
760°C1,400 °F

Same in both: Min Service Temperature -253°C-423 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1.25×10⁻⁶ Ω·m49.2 µΩ·in
1.22×10⁻⁶ Ω·m48 µΩ·in

Same in both: Electrical Conductivity 1.4 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 78 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability Rating (AISI 1212 = 100 %)

14%
12%

Weldability

70 / 100
40 / 100

Formability (cold)

55 / 100
15 / 100

Castability

45 / 100
35 / 100

Brazeability / Solderability

55 / 100
45 / 100

Polishability

80 / 100
70 / 100

Same in both: Machinability 18 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

250 MJ/kg107,481 BTU/lb
290 MJ/kg124,678 BTU/lb

Embodied Carbon (primary production)

16 kg CO₂/kg
17.5 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

118 kN·m/kg
145 kN·m/kg

Specific Stiffness (E / density)

24.4 MN·m/kg
25.8 MN·m/kg

Modulus of Resilience

756 kJ/m³
1,552 kJ/m³

Thermal Diffusivity

3.2 mm²/s
3.4 mm²/s

Thermal Shock Resistance Index

4
5

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.

2005001,0006.577.588.59Density (g/cm³)Yield strength (MPa) — log scaleInconel 718X-750

Manufacturing and finishing

CapabilityInconel 718X-750
CNC machiningYes—
Sheet metalYes—
3D printingYes—
Default conditionSolution Annealed—
Relative cost$$$ Premium$$$$ High
Min. machined wall1.5 mm—
Best machined surfaceRa 1.6 µm—
ElectropolishingYes—
HVOF CoatingYes—

They share 3 finishes: Gold Plating, Plasma Spray, Silver Plating.

Inconel 718 vs X-750 — frequently asked

Is X-750 stronger than Inconel 718?

Yes. X-750 has a typical yield strength of 815 MPa (118 ksi) against 550 MPa (79.8 ksi) for Inconel 718 — about 48% more. Tensile strength is 1,200 MPa (174 ksi) vs 965 MPa (140 ksi).

Which is cheaper, Inconel 718 or X-750?

Inconel 718 is the lower-cost material: it sits in the premium tier ($$$) while X-750 is high ($$$$). 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 X-750?

Inconel 718. Its weldability rates very good (70/100) against fair (40/100) for X-750.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Inconel 718 and X-750 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.