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Nickel Alloy Alloy 825 vs Hastelloy X

Nickel Alloy · grade comparison

Nickel Alloy Alloy 825 and Hastelloy X are both nickel alloy grades. Hastelloy X is the stronger of the two: yield strength 360 MPa (52.2 ksi) against 310 MPa (45 ksi) for Alloy 825, about 16% more; tensile strength follows at 755 MPa (110 ksi) vs 690 MPa (100 ksi). Hastelloy X is harder — 195 HB against 150 HB for Alloy 825 — which matters for wear surfaces and threads. Hastelloy X runs hotter in service (1,150°C vs 540°C continuous) and Alloy 825 conducts heat better (11.1 W/m·K vs 9.1 W/m·K). On the shop floor, Alloy 825 forms better (80 vs 70 out of 100) and Hastelloy X sits in a lower cost tier (premium, $$$) than Alloy 825 (high, $$$$).

Hastelloy XChoose it when strength drives the design, or when surface hardness matters.

Alloy 825 vs Hastelloy X: properties

Alloy 825Hastelloy X

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196 GPa28.4 Msi
205 GPa29.7 Msi

Shear Modulus

76 GPa11 Msi
79 GPa11.5 Msi

Bulk Modulus

163 GPa23.6 Msi
190 GPa27.6 Msi

Poisson's Ratio

0.3
0.32

Tensile Strength (Ultimate)

690 MPa100 ksi
755 MPa110 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
360 MPa52.2 ksi

Elongation at Break

45%
43%

Reduction in Area

60%
55%

Shear Strength

450 MPa65.3 ksi
490 MPa71.1 ksi

Charpy V-Notch Impact (RT)

200 J148 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

150 HB
195 HB

Hardness, Rockwell B

82 HRB
90 HRB

Hardness, Vickers

160 HV
205 HV

Compressive Strength

—
370 MPa53.7 ksi

Fracture Toughness (K_IC)

—
120 MPa·√m109 ksi·√in

Same in both: Fatigue Strength (Endurance Limit) 300 MPa43.5 ksi

Physical

Density and transition temperatures.

Density

8.14 g/cm³0.29 lb/in³
8.22 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,370°C2,498 °F
1,260°C2,300 °F

Liquidus Temperature

1,400°C2,552 °F
1,355°C2,471 °F

Thermal

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

Thermal Conductivity

11.1 W/m·K6.4 BTU/hr·ft·°F
9.1 W/m·K5.3 BTU/hr·ft·°F

Specific Heat Capacity

440 J/kg·K0.11 BTU/lb·°F
486 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14 µm/m·K7.8 µin/in·°F
13.9 µm/m·K7.7 µin/in·°F

Latent Heat of Fusion

295 J/g127 BTU/lb
290 J/g125 BTU/lb

Max Service Temperature (continuous)

540°C1,004 °F
1,150°C2,102 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1.13×10⁻⁶ Ω·m44.5 µΩ·in
1.18×10⁻⁶ Ω·m46.5 µΩ·in

Same in both: Electrical Conductivity 1.5 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

82 / 100
76 / 100

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

25 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

14%
12%

Formability (cold)

80 / 100
70 / 100

Castability

30 / 100
55 / 100

Brazeability / Solderability

60 / 100
80 / 100

Polishability

75 / 100
70 / 100

Same in both: Weldability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

115 MJ/kg49,441 BTU/lb
215 MJ/kg92,433 BTU/lb

Embodied Carbon (primary production)

8.5 kg CO₂/kg
13.5 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
520 L/kg62.3 gal/lb

Typical Recycled Content

45%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

85 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

24.1 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

245 kJ/m³
316 kJ/m³

Thermal Diffusivity

3.1 mm²/s
2.3 mm²/s

Thermal Shock Resistance Index

3
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 XAlloy 825

Manufacturing and finishing

CapabilityAlloy 825Hastelloy 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.

Alloy 825 vs Hastelloy X — frequently asked

Is Hastelloy X stronger than Alloy 825?

Yes. Hastelloy X has a typical yield strength of 360 MPa (52.2 ksi) against 310 MPa (45 ksi) for Alloy 825 — about 16% more. Tensile strength is 755 MPa (110 ksi) vs 690 MPa (100 ksi).

Which is cheaper, Alloy 825 or Hastelloy X?

Hastelloy X is the lower-cost material: it sits in the premium tier ($$$) while Alloy 825 is high ($$$$). 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, Alloy 825 or Hastelloy X?

Alloy 825, by a small margin. Both rate poor for machinability — 25/100 against 18/100 for Hastelloy X.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Alloy 825 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.