Steel 18Ni(400) vs Maraging 300
Steel · grade comparison
Steel 18Ni(400) and Maraging 300 are both steel grades. 18Ni(400) is the stronger of the two: yield strength 2,680 MPa (389 ksi) against 800 MPa (116 ksi) for Maraging 300, about 3.4 times as much; tensile strength follows at 2,760 MPa (400 ksi) vs 1,010 MPa (146 ksi). In exchange, Maraging 300 is the more ductile: elongation 17% versus 6% for 18Ni(400), and 18Ni(400) is harder (58 HRC vs 30 HRC). 18Ni(400) is stiffer (200 GPa vs 180 GPa) and Maraging 300 conducts heat better (20 W/m·K vs 18 W/m·K). On the shop floor, Maraging 300 machines more easily (fair vs poor), Maraging 300 welds better (80 vs 70 out of 100), and Maraging 300 sits in a lower cost tier (standard, $$) than 18Ni(400) (high, $$$$).
18Ni(400)Choose it when strength drives the design.
Maraging 300Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
18Ni(400) vs Maraging 300: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Hardness, Brinell
Same in both: Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Min Service Temperature
Same in both: Specific Heat Capacity 450 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Same in both: Embodied Carbon (primary production) 6.5 kg CO₂/kg · Typical Recycled Content 20%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 18Ni(400) | Maraging 300 |
|---|---|---|
| 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 300 — frequently asked
Is 18Ni(400) stronger than Maraging 300?
Yes. 18Ni(400) has a typical yield strength of 2,680 MPa (389 ksi) against 800 MPa (116 ksi) for Maraging 300 — about 3.4 times as much. Tensile strength is 2,760 MPa (400 ksi) vs 1,010 MPa (146 ksi).
Which is cheaper, 18Ni(400) or Maraging 300?
Maraging 300 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 300?
Maraging 300. Its machinability rates fair (45/100) against poor (18/100) for 18Ni(400); for welding the order is Maraging 300 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 300 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.