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Nickel Alloy Hastelloy S vs Hastelloy X

Nickel Alloy · grade comparison

Nickel Alloy Hastelloy S and Hastelloy X are both nickel alloy grades. Hastelloy S is the stronger of the two: yield strength 455 MPa (66 ksi) against 360 MPa (52.2 ksi) for Hastelloy X, about 26% more; tensile strength follows at 895 MPa (130 ksi) vs 755 MPa (110 ksi). Hastelloy S is the more ductile: elongation 50% versus 43% for Hastelloy X. Hastelloy X is lighter (8.22 g/cm³ vs 8.76 g/cm³ for Hastelloy S) and Hastelloy X runs hotter in service (1,150°C vs 1,050°C continuous). On the shop floor, Hastelloy X sits in a lower cost tier (premium, $$$) than Hastelloy S (high, $$$$).

Hastelloy SChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Hastelloy XChoose it when weight is the constraint, or when the part sees heat.

Hastelloy S vs Hastelloy X: properties

Hastelloy SHastelloy X

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

212 GPa30.7 Msi
205 GPa29.7 Msi

Shear Modulus

81 GPa11.7 Msi
79 GPa11.5 Msi

Bulk Modulus

186 GPa27 Msi
190 GPa27.6 Msi

Poisson's Ratio

0.31
0.32

Tensile Strength (Ultimate)

895 MPa130 ksi
755 MPa110 ksi

Yield Strength (0.2% offset)

455 MPa66 ksi
360 MPa52.2 ksi

Elongation at Break

50%
43%

Shear Strength

555 MPa80.5 ksi
490 MPa71.1 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
300 MPa43.5 ksi

Charpy V-Notch Impact (RT)

190 J140 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

200 HB
195 HB

Hardness, Rockwell B

92 HRB
90 HRB

Compressive Strength

—
370 MPa53.7 ksi

Fracture Toughness (K_IC)

—
120 MPa·√m109 ksi·√in

Hardness, Vickers

—
205 HV

Same in both: Reduction in Area 55%

Physical

Density and transition temperatures.

Density

8.76 g/cm³0.32 lb/in³
8.22 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,335°C2,435 °F
1,260°C2,300 °F

Liquidus Temperature

1,380°C2,516 °F
1,355°C2,471 °F

Thermal

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

Thermal Conductivity

10.7 W/m·K6.2 BTU/hr·ft·°F
9.1 W/m·K5.3 BTU/hr·ft·°F

Specific Heat Capacity

420 J/kg·K0.1 BTU/lb·°F
486 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.6 µm/m·K6.4 µin/in·°F
13.9 µm/m·K7.7 µin/in·°F

Max Service Temperature (continuous)

1,050°C1,922 °F
1,150°C2,102 °F

Min Service Temperature

-253°C-423 °F
-196°C-321 °F

Latent Heat of Fusion

—
290 J/g125 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

1.4 % IACS
1.5 % IACS

Electrical Resistivity

1.26×10⁻⁶ Ω·m49.6 µΩ·in
1.18×10⁻⁶ Ω·m46.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.15 V
-0.1 V

Corrosion Resistance

82 / 100
76 / 100

Manufacturability

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

Machinability

24 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

13%
12%

Formability (cold)

80 / 100
70 / 100

Castability

35 / 100
55 / 100

Same in both: Weldability 85 / 100 · Brazeability / Solderability 80 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

150 MJ/kg64,488 BTU/lb
215 MJ/kg92,433 BTU/lb

Embodied Carbon (primary production)

12.5 kg CO₂/kg
13.5 kg CO₂/kg

Embodied Water

260 L/kg31.2 gal/lb
520 L/kg62.3 gal/lb

Typical Recycled Content

40%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

102 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

24.2 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

488 kJ/m³
316 kJ/m³

Thermal Diffusivity

2.9 mm²/s
2.3 mm²/s

Thermal Shock Resistance Index

4
2

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 scaleHastelloy XHastelloy S

Manufacturing and finishing

CapabilityHastelloy SHastelloy X
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.

Hastelloy S vs Hastelloy X — frequently asked

Is Hastelloy S stronger than Hastelloy X?

Yes. Hastelloy S has a typical yield strength of 455 MPa (66 ksi) against 360 MPa (52.2 ksi) for Hastelloy X — about 26% more. Tensile strength is 895 MPa (130 ksi) vs 755 MPa (110 ksi).

Which is cheaper, Hastelloy S or Hastelloy X?

Hastelloy X is the lower-cost material: it sits in the premium tier ($$$) while Hastelloy S is high ($$$$). 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, Hastelloy S or Hastelloy X?

Hastelloy S, by a small margin. Both rate poor for machinability — 24/100 against 18/100 for Hastelloy X.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Hastelloy S and Hastelloy X 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.