Steel 18Ni(350) Maraging Steel vs Custom 455
Steel · grade comparison
Steel 18Ni(350) Maraging Steel and Custom 455 are both steel grades. 18Ni(350) Maraging Steel is the stronger of the two: yield strength 2,320 MPa (336 ksi) against 1,450 MPa (210 ksi) for Custom 455, about 60% more; tensile strength follows at 2,400 MPa (348 ksi) vs 1,550 MPa (225 ksi). In exchange, Custom 455 is the more ductile: elongation 12% versus 7% for 18Ni(350) Maraging Steel, and 18Ni(350) Maraging Steel is harder (56 HRC vs 46 HRC). Custom 455 is lighter (7.76 g/cm³ vs 8.08 g/cm³ for 18Ni(350) Maraging Steel) and Custom 455 is stiffer (200 GPa vs 190 GPa). On the shop floor, 18Ni(350) Maraging Steel welds better (good vs fair).
18Ni(350) Maraging SteelChoose it when strength drives the design, or when it will be welded.
Custom 455Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
18Ni(350) Maraging Steel vs Custom 455: 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 SteelCustom 455
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)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 270 J/g116 BTU/lb
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
Same in both: Polishability 80 / 100
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 | Custom 455 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
18Ni(350) Maraging Steel vs Custom 455 — frequently asked
Is 18Ni(350) Maraging Steel stronger than Custom 455?
Yes. 18Ni(350) Maraging Steel has a typical yield strength of 2,320 MPa (336 ksi) against 1,450 MPa (210 ksi) for Custom 455 — about 60% more. Tensile strength is 2,400 MPa (348 ksi) vs 1,550 MPa (225 ksi).
Which is cheaper, 18Ni(350) Maraging Steel or Custom 455?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 18Ni(350) Maraging Steel or Custom 455?
18Ni(350) Maraging Steel. Its weldability rates good (55/100) against fair (45/100) for Custom 455.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18Ni(350) Maraging Steel and Custom 455 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.