Steel 18Ni(190) vs 18Ni(400)
Steel · grade comparison
Steel 18Ni(190) and 18Ni(400) are both steel grades. 18Ni(400) is the stronger of the two: yield strength 2,680 MPa (389 ksi) against 1,280 MPa (186 ksi) for 18Ni(190), about 109% more; tensile strength follows at 2,760 MPa (400 ksi) vs 1,330 MPa (193 ksi). In exchange, 18Ni(190) is the more ductile: elongation 14% versus 6% for 18Ni(400), and 18Ni(400) is harder (58 HRC vs 40 HRC). 18Ni(400) is stiffer (200 GPa vs 190 GPa) and 18Ni(190) conducts heat better (20.9 W/m·K vs 18 W/m·K). On the shop floor, 18Ni(190) machines more easily (fair vs poor) and 18Ni(190) welds better (excellent vs very good).
18Ni(190)Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
18Ni(400)Choose it when strength drives the design.
18Ni(190) vs 18Ni(400): 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, Brinell
Hardness, Rockwell C
Hardness, Vickers
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
Specific Heat Capacity
Min Service Temperature
Same in both: 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
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
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(190) | 18Ni(400) |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
18Ni(190) vs 18Ni(400) — frequently asked
Is 18Ni(400) stronger than 18Ni(190)?
Yes. 18Ni(400) has a typical yield strength of 2,680 MPa (389 ksi) against 1,280 MPa (186 ksi) for 18Ni(190) — about 109% more. Tensile strength is 2,760 MPa (400 ksi) vs 1,330 MPa (193 ksi).
Which is cheaper, 18Ni(190) or 18Ni(400)?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 18Ni(190) or 18Ni(400)?
18Ni(190). Its machinability rates fair (35/100) against poor (18/100) for 18Ni(400); for welding the order is 18Ni(190) first (excellent, 85/100) then 18Ni(400) (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18Ni(190) and 18Ni(400) 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.