Steel 18Ni(350) Maraging Steel vs 40CrNiMoA
Steel · grade comparison
Steel 18Ni(350) Maraging Steel and 40CrNiMoA are both steel grades. 18Ni(350) Maraging Steel is the stronger of the two: yield strength 2,320 MPa (336 ksi) against 950 MPa (138 ksi) for 40CrNiMoA, about 144% more; tensile strength follows at 2,400 MPa (348 ksi) vs 1,080 MPa (157 ksi). In exchange, 40CrNiMoA is the more ductile: elongation 16% versus 7% for 18Ni(350) Maraging Steel, and 18Ni(350) Maraging Steel is harder (56 HRC vs 34 HRC). 40CrNiMoA is stiffer (207 GPa vs 190 GPa) and 40CrNiMoA conducts heat better (44 W/m·K vs 20 W/m·K). On the shop floor, 40CrNiMoA machines more easily (fair vs poor), 18Ni(350) Maraging Steel welds better (good vs poor), and 40CrNiMoA sits in a lower cost tier (standard, $$) than 18Ni(350) Maraging Steel (high, $$$$).
18Ni(350) Maraging SteelChoose it when strength drives the design, or when it will be welded.
40CrNiMoAChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
18Ni(350) Maraging Steel vs 40CrNiMoA: 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.
18Ni(350) Maraging Steel40CrNiMoA
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Poisson's Ratio
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: Bulk Modulus 160 GPa23.2 Msi
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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Min Service Temperature
Same in both: 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)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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(350) Maraging Steel | 40CrNiMoA |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | Q&T |
| 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(350) Maraging Steel vs 40CrNiMoA — frequently asked
Is 18Ni(350) Maraging Steel stronger than 40CrNiMoA?
Yes. 18Ni(350) Maraging Steel has a typical yield strength of 2,320 MPa (336 ksi) against 950 MPa (138 ksi) for 40CrNiMoA — about 144% more. Tensile strength is 2,400 MPa (348 ksi) vs 1,080 MPa (157 ksi).
Which is cheaper, 18Ni(350) Maraging Steel or 40CrNiMoA?
40CrNiMoA is the lower-cost material: it sits in the standard tier ($$) while 18Ni(350) Maraging Steel is high ($$$$). 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(350) Maraging Steel or 40CrNiMoA?
40CrNiMoA. Its machinability rates fair (42/100) against poor (22/100) for 18Ni(350) Maraging Steel; for welding the order is 18Ni(350) Maraging Steel first (good, 55/100) then 40CrNiMoA (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18Ni(350) Maraging Steel and 40CrNiMoA 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.