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Nickel Alloy Astroloy vs Inconel 718

Nickel Alloy · grade comparison

Nickel Alloy Astroloy and Inconel 718 are both nickel alloy grades. Astroloy is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 550 MPa (79.8 ksi) for Inconel 718, about 91% more; tensile strength follows at 1,415 MPa (205 ksi) vs 965 MPa (140 ksi). In exchange, Inconel 718 is the more ductile: elongation 45% versus 16% for Astroloy, and Astroloy is harder (375 HB vs 200 HB). Astroloy is lighter (7.91 g/cm³ vs 8.19 g/cm³ for Inconel 718) and Astroloy is stiffer (213 GPa vs 200 GPa). On the shop floor, Inconel 718 welds better (very good vs not recommended) and Inconel 718 sits in a lower cost tier (premium, $$$) than Astroloy (high, $$$$).

AstroloyChoose it when strength drives the design, or when weight is the constraint.

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

Astroloy vs Inconel 718: properties

AstroloyInconel 718

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

213 GPa30.9 Msi
200 GPa29 Msi

Shear Modulus

82 GPa11.9 Msi
78 GPa11.3 Msi

Bulk Modulus

178 GPa25.8 Msi
163 GPa23.6 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

1,415 MPa205 ksi
965 MPa140 ksi

Yield Strength (0.2% offset)

1,050 MPa152 ksi
550 MPa79.8 ksi

Elongation at Break

16%
45%

Reduction in Area

18%
55%

Compressive Strength

1,080 MPa157 ksi
—

Shear Strength

880 MPa128 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

620 MPa89.9 ksi
420 MPa60.9 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

375 HB
200 HB

Hardness, Rockwell C

40 HRC
—

Hardness, Vickers

400 HV
210 HV

Hardness, Rockwell B

—
92 HRB

Physical

Density and transition temperatures.

Density

7.91 g/cm³0.29 lb/in³
8.19 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,250°C2,282 °F
1,260°C2,300 °F

Liquidus Temperature

1,340°C2,444 °F
1,336°C2,437 °F

Thermal

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

Thermal Conductivity

11 W/m·K6.4 BTU/hr·ft·°F
11.4 W/m·K6.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
13 µm/m·K7.2 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

815°C1,499 °F
540°C1,004 °F

Min Service Temperature

-200°C-328 °F
-253°C-423 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.3 % IACS
1.4 % IACS

Electrical Resistivity

1.31×10⁻⁶ Ω·m51.6 µΩ·in
1.25×10⁻⁶ Ω·m49.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.15 V
-0.1 V

Corrosion Resistance

62 / 100
78 / 100

Manufacturability

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

Machinability

12 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

8%
14%

Weldability

10 / 100
70 / 100

Formability (cold)

8 / 100
55 / 100

Castability

35 / 100
45 / 100

Brazeability / Solderability

40 / 100
55 / 100

Polishability

70 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

240 MJ/kg103,182 BTU/lb
250 MJ/kg107,481 BTU/lb

Embodied Water

320 L/kg38.3 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

15%
35%

Same in both: Embodied Carbon (primary production) 16 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

179 kN·m/kg
118 kN·m/kg

Specific Stiffness (E / density)

26.9 MN·m/kg
24.4 MN·m/kg

Modulus of Resilience

2,588 kJ/m³
756 kJ/m³

Thermal Diffusivity

3.3 mm²/s
3.2 mm²/s

Thermal Shock Resistance Index

6
4

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 718Astroloy

Manufacturing and finishing

CapabilityAstroloyInconel 718
CNC machining—Yes
Sheet metal—Yes
3D printing—Yes
Default condition—Solution Annealed
Relative cost$$$$ High$$$ Premium
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.

Astroloy vs Inconel 718 — frequently asked

Is Astroloy stronger than Inconel 718?

Yes. Astroloy has a typical yield strength of 1,050 MPa (152 ksi) against 550 MPa (79.8 ksi) for Inconel 718 — about 91% more. Tensile strength is 1,415 MPa (205 ksi) vs 965 MPa (140 ksi).

Which is cheaper, Astroloy or Inconel 718?

Inconel 718 is the lower-cost material: it sits in the premium tier ($$$) while Astroloy is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, Astroloy or Inconel 718?

Inconel 718. Its machinability rates poor (18/100) against not recommended (12/100) for Astroloy; for welding the order is Inconel 718 first (very good, 70/100) then Astroloy (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Astroloy 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.