Stainless Steel 304 vs 430
Stainless Steel · grade comparison
Stainless Steel 304 and 430 are both stainless steel grades. 430 is the stronger of the two: yield strength 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 304, about 24% more. In exchange, 304 is the more ductile: elongation 55% versus 30% for 430. 430 is lighter (7.7 g/cm³ vs 8 g/cm³ for 304) and 430 conducts heat better (26 W/m·K vs 16.2 W/m·K). On the shop floor, 304 welds better (excellent vs good).
304Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
430Choose it when strength drives the design, or when weight is the constraint.
Buyer's decision notes
Choose 304 for austenitic formability, robust welding practice and wider corrosion-service use. Choose 430 for mildly corrosive formed products where ferritic behavior, stable nickel-free alloying economics and magnetic response suit the assembly.
Compare the same condition
Neither route names temper, thickness or finish. Compare the same flat-rolled product form and gauge, and keep annealed or cold-worked condition explicit; magnetic response and mechanical properties can change with processing.
- Environment
- Outokumpu positions 430 for mildly corrosive environments and notes lower localized-corrosion resistance than 304 in chloride-containing media. Validate cleaners, condensation, salts and crevices rather than assigning either grade a universal indoor or outdoor label.
- Magnetic design
- 430 is ferritic and normally magnetic. Do not specify 304 as universally nonmagnetic: cold work, weld structure and the measurement method can affect its magnetic response. Put a measurable magnetic requirement on the drawing if it is functional.
- Forming and welding
- 304 generally offers more forming latitude and established welding options. For 430, review bend direction, edge quality, weld heat input and the chosen stabilized or unstabilized ferritic grade rather than transferring a 304 process unchanged.
- Appearance and heat
- Match surface finish, grain direction and supplier lot for visible panels. If thermal cycling or a mixed-material joint is involved, include thermal expansion and joint movement in the comparison, not just room-temperature strength.
Put this on the RFQ
- State exact grade, flat-product specification, condition, gauge, surface designation, protective film and visible side.
- Define bend and draw severity, welding route, cosmetic weld treatment and any functional magnetic acceptance test.
- Describe chloride and cleaning exposure, operating temperature, crevices and dissimilar-metal contacts.
Primary references
- Outokumpu — Moda 430 range — Producer datasheet for ferritic 430-family products, including localized-corrosion and fabrication guidance.
- ASTM — A240/A240M — Active specification for chromium and chromium-nickel stainless plate, sheet and strip.
FabDigit resources: 304 datasheet, 430 datasheet, CNC design guide and sheet-metal design guide.
304 vs 430: 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.
Elastic (Young's) Modulus
Bulk 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, Brinell
Same in both: Shear Modulus 77 GPa11.2 Msi · Hardness, Rockwell B 82 HRB · Hardness, Vickers 160 HV
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
Max Service Temperature (continuous)
Min Service Temperature
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)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 70%
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 stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 304 | 430 |
|---|---|---|
| Casting & forging | Yes | — |
| Default condition | Annealed | Annealed |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 32 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, CrN, DLC, Electroless Nickel (EN), Electropolishing and 20 more.
304 vs 430 — frequently asked
Is 430 stronger than 304?
Yes. 430 has a typical yield strength of 310 MPa (45 ksi) against 250 MPa (36.3 ksi) for 304 — about 24% more. Tensile strength is 500 MPa (72.5 ksi) vs 585 MPa (84.8 ksi).
Which is cheaper, 304 or 430?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 304 or 430?
430, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 304; for welding the order is 304 first (excellent, 88/100) then 430 (good, 60/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 304 and 430 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.