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Nickel Alloy 800 vs Inconel 625

Nickel Alloy · grade comparison

Nickel Alloy 800 and Inconel 625 are both nickel alloy grades. Inconel 625 is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 250 MPa (36.3 ksi) for 800, about 96% more; tensile strength follows at 930 MPa (135 ksi) vs 600 MPa (87 ksi). Inconel 625 is harder — 190 HB against 138 HB for 800 — which matters for wear surfaces and threads. 800 is lighter (7.94 g/cm³ vs 8.44 g/cm³ for Inconel 625) and Inconel 625 is stiffer (207.5 GPa vs 196.5 GPa). On the shop floor, 800 machines more easily (30 vs 18 out of 100) and Inconel 625 sits in a lower cost tier (premium, $$$) than 800 (high, $$$$).

800Choose it when weight is the constraint, or when the part sees heat.

Inconel 625Choose it when strength drives the design, or when surface hardness matters.

800 vs Inconel 625: properties

800Inconel 625

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

196.5 GPa28.5 Msi
207.5 GPa30.1 Msi

Shear Modulus

76.5 GPa11.1 Msi
79 GPa11.5 Msi

Bulk Modulus

203 GPa29.4 Msi
155 GPa22.5 Msi

Poisson's Ratio

0.34
0.28

Tensile Strength (Ultimate)

600 MPa87 ksi
930 MPa135 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
490 MPa71.1 ksi

Reduction in Area

60%
55%

Compressive Strength

250 MPa36.3 ksi
500 MPa72.5 ksi

Shear Strength

400 MPa58 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
420 MPa60.9 ksi

Charpy V-Notch Impact (RT)

160 J118 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

138 HB
190 HB

Hardness, Rockwell B

80 HRB
92 HRB

Hardness, Vickers

145 HV
200 HV

Fracture Toughness (K_IC)

—
110 MPa·√m100 ksi·√in

Same in both: Elongation at Break 45%

Physical

Density and transition temperatures.

Density

7.94 g/cm³0.29 lb/in³
8.44 g/cm³0.3 lb/in³

Melting Point (Solidus)

1,357°C2,475 °F
1,290°C2,354 °F

Liquidus Temperature

1,385°C2,525 °F
1,350°C2,462 °F

Thermal

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

Thermal Conductivity

11.5 W/m·K6.6 BTU/hr·ft·°F
9.8 W/m·K5.7 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
410 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14.4 µm/m·K8 µin/in·°F
12.8 µm/m·K7.1 µin/in·°F

Max Service Temperature (continuous)

815°C1,499 °F
650°C1,202 °F

Min Service Temperature

-196°C-321 °F
-253°C-423 °F

Same in both: Latent Heat of Fusion 290 J/g125 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

1.7 % IACS
1.3 % IACS

Electrical Resistivity

9.89×10⁻⁷ Ω·m38.9 µΩ·in
1.29×10⁻⁶ Ω·m50.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.15 V
-0.1 V

Corrosion Resistance

75 / 100
90 / 100

Manufacturability

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

Machinability

30 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

28%
12%

Weldability

85 / 100
88 / 100

Formability (cold)

78 / 100
70 / 100

Polishability

70 / 100
72 / 100

Castability

—
45 / 100

Same in both: Brazeability / Solderability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
225 MJ/kg96,733 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
14 kg CO₂/kg

Typical Recycled Content

40%
35%

Same in both: Embodied Water 300 L/kg35.9 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
110 kN·m/kg

Specific Stiffness (E / density)

24.7 MN·m/kg
24.6 MN·m/kg

Modulus of Resilience

159 kJ/m³
579 kJ/m³

Thermal Diffusivity

3.1 mm²/s
2.8 mm²/s

Thermal Shock Resistance Index

2
3

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 625800

Manufacturing and finishing

Capability800Inconel 625
CNC machining—Yes
Sheet metal—Yes
3D printing—Yes
Default condition—O
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.

800 vs Inconel 625 — frequently asked

Is Inconel 625 stronger than 800?

Yes. Inconel 625 has a typical yield strength of 490 MPa (71.1 ksi) against 250 MPa (36.3 ksi) for 800 — about 96% more. Tensile strength is 930 MPa (135 ksi) vs 600 MPa (87 ksi).

Which is cheaper, 800 or Inconel 625?

Inconel 625 is the lower-cost material: it sits in the premium tier ($$$) while 800 is high ($$$$). 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, 800 or Inconel 625?

800, by a small margin. Both rate poor for machinability — 30/100 against 18/100 for Inconel 625.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 800 and Inconel 625 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.