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Nickel Alloy Inconel 601 vs Inconel 625

Nickel Alloy · grade comparison

Nickel Alloy Inconel 601 and Inconel 625 are both nickel alloy grades. Inconel 625 is the stronger of the two: yield strength 490 MPa (71.1 ksi) against 310 MPa (45 ksi) for Inconel 601, about 58% more; tensile strength follows at 930 MPa (135 ksi) vs 690 MPa (100 ksi). Inconel 625 is harder — 190 HB against 150 HB for Inconel 601 — which matters for wear surfaces and threads. Inconel 601 is lighter (8.11 g/cm³ vs 8.44 g/cm³ for Inconel 625) and Inconel 601 runs hotter in service (1,150°C vs 650°C continuous). On the shop floor, Inconel 601 machines more easily (28 vs 18 out of 100), Inconel 625 welds better (excellent vs very good), and Inconel 625 sits in a lower cost tier (premium, $$$) than Inconel 601 (high, $$$$).

Inconel 601Choose 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.

Inconel 601 vs Inconel 625: properties

Inconel 601Inconel 625

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
207.5 GPa30.1 Msi

Bulk Modulus

180 GPa26.1 Msi
155 GPa22.5 Msi

Poisson's Ratio

0.31
0.28

Tensile Strength (Ultimate)

690 MPa100 ksi
930 MPa135 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
490 MPa71.1 ksi

Reduction in Area

60%
55%

Shear Strength

470 MPa68.2 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
420 MPa60.9 ksi

Charpy V-Notch Impact (RT)

170 J125 ft·lbf
120 J88.5 ft·lbf

Hardness, Brinell

150 HB
190 HB

Hardness, Rockwell B

80 HRB
92 HRB

Hardness, Vickers

160 HV
200 HV

Compressive Strength

—
500 MPa72.5 ksi

Same in both: Shear Modulus 79 GPa11.5 Msi · Elongation at Break 45% · Fracture Toughness (K_IC) 110 MPa·√m100 ksi·√in

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,360°C2,480 °F
1,290°C2,354 °F

Liquidus Temperature

1,411°C2,572 °F
1,350°C2,462 °F

Thermal

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

Thermal Conductivity

11.2 W/m·K6.5 BTU/hr·ft·°F
9.8 W/m·K5.7 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

13.8 µm/m·K7.7 µin/in·°F
12.8 µm/m·K7.1 µin/in·°F

Max Service Temperature (continuous)

1,150°C2,102 °F
650°C1,202 °F

Min Service Temperature

-196°C-321 °F
-253°C-423 °F

Latent Heat of Fusion

—
290 J/g125 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

1.5 % IACS
1.3 % IACS

Electrical Resistivity

1.19×10⁻⁶ Ω·m46.9 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

78 / 100
90 / 100

Manufacturability

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

Machinability

28 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

13%
12%

Weldability

78 / 100
88 / 100

Formability (cold)

72 / 100
70 / 100

Castability

25 / 100
45 / 100

Brazeability / Solderability

60 / 100
65 / 100

Polishability

70 / 100
72 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

145 MJ/kg62,339 BTU/lb
225 MJ/kg96,733 BTU/lb

Embodied Carbon (primary production)

13 kg CO₂/kg
14 kg CO₂/kg

Embodied Water

320 L/kg38.3 gal/lb
300 L/kg35.9 gal/lb

Typical Recycled Content

40%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

85 kN·m/kg
110 kN·m/kg

Specific Stiffness (E / density)

25.4 MN·m/kg
24.6 MN·m/kg

Modulus of Resilience

233 kJ/m³
579 kJ/m³

Thermal Diffusivity

3.1 mm²/s
2.8 mm²/s

Same in both: Thermal Shock Resistance Index 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 625Inconel 601

Manufacturing and finishing

CapabilityInconel 601Inconel 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.

Inconel 601 vs Inconel 625 — frequently asked

Is Inconel 625 stronger than Inconel 601?

Yes. Inconel 625 has a typical yield strength of 490 MPa (71.1 ksi) against 310 MPa (45 ksi) for Inconel 601 — about 58% more. Tensile strength is 930 MPa (135 ksi) vs 690 MPa (100 ksi).

Which is cheaper, Inconel 601 or Inconel 625?

Inconel 625 is the lower-cost material: it sits in the premium tier ($$$) while Inconel 601 is high ($$$$). 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, Inconel 601 or Inconel 625?

Inconel 601, by a small margin. Both rate poor for machinability — 28/100 against 18/100 for Inconel 625; for welding the order is Inconel 625 first (excellent, 88/100) then Inconel 601 (very good, 78/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Inconel 601 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.