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Steel 18Ni(400) vs Maraging 250

Steel · grade comparison

Steel 18Ni(400) and Maraging 250 are both steel grades. 18Ni(400) is the stronger of the two: yield strength 2,680 MPa (389 ksi) against 810 MPa (117 ksi) for Maraging 250, about 3.3 times as much; tensile strength follows at 2,760 MPa (400 ksi) vs 1,010 MPa (146 ksi). In exchange, Maraging 250 is the more ductile: elongation 18% versus 6% for 18Ni(400), and 18Ni(400) is harder (58 HRC vs 30 HRC). 18Ni(400) is stiffer (200 GPa vs 181 GPa) and Maraging 250 conducts heat better (25.5 W/m·K vs 18 W/m·K). On the shop floor, Maraging 250 machines more easily (fair vs poor), Maraging 250 welds better (80 vs 70 out of 100), and Maraging 250 sits in a lower cost tier (standard, $$) than 18Ni(400) (high, $$$$).

18Ni(400)Choose it when strength drives the design.

Maraging 250Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

18Ni(400) vs Maraging 250: properties

18Ni(400)Maraging 250

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
181 GPa26.3 Msi

Shear Modulus

77 GPa11.2 Msi
70 GPa10.2 Msi

Bulk Modulus

165 GPa23.9 Msi
155 GPa22.5 Msi

Tensile Strength (Ultimate)

2,760 MPa400 ksi
1,010 MPa146 ksi

Yield Strength (0.2% offset)

2,680 MPa389 ksi
810 MPa117 ksi

Elongation at Break

6%
18%

Reduction in Area

28%
72%

Compressive Strength

2,800 MPa406 ksi
830 MPa120 ksi

Shear Strength

1,650 MPa239 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

800 MPa116 ksi
450 MPa65.3 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
—

Charpy V-Notch Impact (RT)

8 J5.9 ft·lbf
130 J95.9 ft·lbf

Hardness, Rockwell C

58 HRC
30 HRC

Hardness, Vickers

655 HV
310 HV

Hardness, Brinell

—
300 HB

Same in both: Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Density

8.1 g/cm³0.29 lb/in³
8 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,400°C2,552 °F
1,413°C2,575 °F

Liquidus Temperature

1,440°C2,624 °F
1,430°C2,606 °F

Thermal

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

Thermal Conductivity

18 W/m·K10.4 BTU/hr·ft·°F
25.5 W/m·K14.7 BTU/hr·ft·°F

Min Service Temperature

-73°C-99 °F
-196°C-321 °F

Same in both: Specific Heat Capacity 450 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.1 µm/m·K5.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.6 % IACS
2.7 % IACS

Electrical Resistivity

6.6×10⁻⁷ Ω·m26 µΩ·in
6.5×10⁻⁷ Ω·m25.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.55 V
-0.58 V

Same in both: Corrosion Resistance 25 / 100

Manufacturability

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

Machinability

18 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
45%

Weldability

70 / 100
80 / 100

Formability (cold)

5 / 100
55 / 100

Brazeability / Solderability

35 / 100
55 / 100

Polishability

80 / 100
85 / 100

Castability

—
35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

6.5 kg CO₂/kg
7 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

20%
30%

Same in both: Embodied Energy (primary production) 90 MJ/kg38,693 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

341 kN·m/kg
126 kN·m/kg

Specific Stiffness (E / density)

24.7 MN·m/kg
22.6 MN·m/kg

Modulus of Resilience

17,956 kJ/m³
1,812 kJ/m³

Thermal Diffusivity

4.9 mm²/s
7.1 mm²/s

Thermal Shock Resistance Index

25
14

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleMaraging 25018Ni(400)

Manufacturing and finishing

Capability18Ni(400)Maraging 250
CNC machining—Yes
Sheet metal—Yes
3D printing—Yes
Default condition—Annealed
Relative cost$$$$ High$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

18Ni(400) vs Maraging 250 — frequently asked

Is 18Ni(400) stronger than Maraging 250?

Yes. 18Ni(400) has a typical yield strength of 2,680 MPa (389 ksi) against 810 MPa (117 ksi) for Maraging 250 — about 3.3 times as much. Tensile strength is 2,760 MPa (400 ksi) vs 1,010 MPa (146 ksi).

Which is cheaper, 18Ni(400) or Maraging 250?

Maraging 250 is the lower-cost material: it sits in the standard tier ($$) while 18Ni(400) is high ($$$$). 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, 18Ni(400) or Maraging 250?

Maraging 250. Its machinability rates fair (45/100) against poor (18/100) for 18Ni(400); for welding the order is Maraging 250 first (very good, 80/100) then 18Ni(400) (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18Ni(400) and Maraging 250 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.