Stainless Steel 409 vs 434
Stainless Steel · grade comparison
Stainless Steel 409 and 434 are both stainless steel grades. 434 is the stronger of the two: yield strength 365 MPa (52.9 ksi) against 250 MPa (36.3 ksi) for 409, about 46% more; tensile strength follows at 530 MPa (76.9 ksi) vs 450 MPa (65.3 ksi). In exchange, 409 is the more ductile: elongation 30% versus 25% for 434, and 434 is harder (160 HB vs 150 HB). 434 runs hotter in service (760°C vs 675°C continuous) and 409 conducts electricity better (2.9 % IACS vs 2.6 % IACS). On the shop floor, 409 welds better (very good vs good).
409Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
434Choose it when strength drives the design, or when the part sees heat.
409 vs 434: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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.
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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 7.7 g/cm³0.28 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°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 Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Same in both: Machinability 55 / 100 · Brazeability / Solderability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 65%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 26 MN·m/kg
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 409 | 434 |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | Annealed | Annealed |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| TiAlN | Yes | — |
| TiB2 | Yes | — |
| TiCN | Yes | — |
| TiN | Yes | — |
| WC/C | Yes | — |
| ZrN | Yes | — |
Both are offered for Sheet metal. They share 16 finishes: Black Oxide, Cerakote, Chrome Plating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Chrome Plating, Nickel Plating, PTFE Coating, Painting, Passivation (Stainless Steel) and 4 more.
409 vs 434 — frequently asked
Is 434 stronger than 409?
Yes. 434 has a typical yield strength of 365 MPa (52.9 ksi) against 250 MPa (36.3 ksi) for 409 — about 46% more. Tensile strength is 530 MPa (76.9 ksi) vs 450 MPa (65.3 ksi).
Which is cheaper, 409 or 434?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 409 or 434?
409. Its weldability rates very good (80/100) against good (55/100) for 434.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 409 and 434 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.