304 vs 430 Stainless Steel: Practical Differences, Use Cases, and Buying Guidance
Choosing between 304 vs 430 stainless steel is rarely a “better vs worse” decision. In most procurement scenarios, it is a controlled trade-off between corrosion performance, fabrication method, magnetic behavior, appearance requirements, and cost stability.
If your project involves food contact, frequent wash-down, outdoor exposure, or welded fabrication, 304 is often the safer baseline. If your application is primarily indoor, cosmetic, appliance-oriented, or cost-sensitive, 430 may deliver the required performance at a lower and more stable alloy cost structure—provided the environment and joining method are appropriate. (Ferritic steels are magnetic and typically nickel-free, which is a major driver behind the cost behavior.) worldstainless+1
Below is a procurement-focused comparison designed for engineers, buyers, and project managers who need to specify the right grade with fewer re-quotes and fewer field issues.
What are 304 and 430 stainless steels?
304 stainless steel (AISI 304 / UNS S30400)
304 is a classic austenitic chromium-nickel stainless steel. Typical chemistry ranges are commonly shown around Cr ~18–20% and Ni ~8–10.5% (ranges depend on the referenced standard). Wikipedia
In the annealed condition, austenitic stainless steels are generally not attracted to a magnet, though they can become slightly magnetic after cold work. nickelinstitute.org+1
430 stainless steel (AISI 430 / UNS S43000)
430 is a widely used ferritic (400-series) stainless steel, typically magnetic, and commonly shown with Cr ~16–18% and very low nickel. Wikipedia+1
World Stainless notes that type 430 (group 2 ferritic) is frequently used worldwide and is often selected as an alternative to 304 mainly for indoor applications. worldstainless
304 vs 430: quick comparison table
| Topic | 304 Stainless Steel | 430 Stainless Steel |
|---|---|---|
| Metallurgy | Austenitic (Cr-Ni) | Ferritic (Fe-Cr) |
| Magnetism | Generally non-magnetic when annealed; may become slightly magnetic after cold work nickelinstitute.org+1 | Magnetic (typical ferritic behavior) worldstainless+1 |
| Corrosion positioning | Broad general-purpose corrosion resistance; common default for many fabricated items | Good in many indoor/mild settings; pitting/crevice resistance is typically lower than austenitic Cr-Ni grades in harsher chloride exposures IRP CDN Website+1 |
| Fabrication & forming | Excellent all-round fabrication; widely used for sinks, kitchen equipment, tanks | Good formability; lower work-hardening and often less springback; tooling can be efficient worldstainless |
| Welding | Austenitic grades (incl. 304) have strong weldability advantages in many fabrications nickelinstitute.org | Weldable but requires more control; some ferritic grades are improved by stabilizers, while standard grades can be more sensitive worldstainless+1 |
| Cost behavior | Nickel-containing; can be more exposed to nickel price volatility worldstainless | Often nickel-free; commonly less exposed to nickel volatility worldstainless |
| Typical uses | Food processing equipment, kitchen equipment, general fabrication | Washing machine drums, indoor panels, household/appliance components, indoor utensils worldstainless |
The decision factors that matter in real purchasing
1) Corrosion resistance: match the environment, not the label
Stainless performance depends on chemistry + surface condition + service environment. World Stainless emphasizes that corrosion resistance is driven primarily by composition, and there is meaningful overlap between ferritics and austenitics depending on grade selection and exposure. worldstainless+1
Practical guidance:
Choose 304 when exposure includes: frequent cleaning chemicals, moisture retention points, outdoor atmospheres, or moderate corrosives—especially where the cost of failure is high.
Consider 430 when exposure is: indoor, dry-to-moderate humidity, cosmetic panels, appliance liners/housings, and similar duty cycles—particularly where the grade is not over-specified.
If your buyer spec is driven by chlorides (coastal air, de-icing salts, brine, marine splash), you should usually evaluate 316/316L rather than forcing 304/430 to do what they were not designed to do. If you need a practical starting point, you can cross-check corrosion risk using a PREN-style comparison (especially for chloride pitting decisions) via LYHSteel’s PREN tool:
https://lyhsteel.com/pren-calculator/ LYH Steel
2) Magnetism: design requirement or misconception?
A common RFQ line is “must be non-magnetic.” In practice:
Austenitic grades such as 304 are generally considered non-magnetic in the annealed condition, but can become magnet-attractive after cold work (forming, bending, heavy deformation). nickelinstitute.org+1
Ferritic grades are magnetic by nature. worldstainless+1
Buying tip: If magnetism is critical (sensors, MRI-adjacent areas, separation systems), specify the condition and forming history, not only the grade name.
3) Forming and shop performance: springback, work hardening, and productivity
Ferritic stainless steels typically show lower work hardening and less springback than austenitics, which can translate into more predictable forming and potentially lower tool wear in certain production setups. worldstainless
304, however, remains a strong choice for complex fabricated products where broad fabrication flexibility is required.
Decision shortcut:
Complex fabrication + broad supplier base + “works in most cases” → 304
High-volume indoor components where cost and forming efficiency matter → 430 (or stabilized ferritic alternatives when welding is involved)
4) Welding and heat-affected-zone risk: do not treat 430 like 304
Nickel Institute guidance highlights that nickel-austenitic grades have notable weldability advantages and are widely fabricated. nickelinstitute.org
World Stainless also indicates that some newer ferritic grades broaden welding applicability, while standard grades require more careful matching of grade and joining approach. worldstainless
Procurement checklist for welded parts:
If the part is welded and corrosion resistance is critical, 304/304L is typically the safer procurement baseline. nickelinstitute.org
If you want a ferritic solution for cost or thermal reasons, consider stabilized ferritic grades (project-dependent) and align welding procedure qualification accordingly. worldstainless
5) Cost and price stability: what you are really buying
Ferritic stainless steels are often positioned for lower cost and reduced exposure to nickel volatility because many are nickel-free. worldstainless
304 is widely available and often competitively priced, but in many markets its surcharge can be more sensitive to nickel movements.
Commercial takeaway: If your project has long lead times and strict budget control, your risk is not only “price per kg” but re-quotation frequency and alloy surcharge surprises.
Application-based recommendations
Use 304 when:
Food processing equipment, sanitary fabrication, frequent wash-down, brewery/winery/dairy equipment
Kitchen equipment where corrosion and cleanability are critical
Tanks, fabricated assemblies, and general industrial components requiring reliable weldability nickelinstitute.org
Use 430 when:
Appliance liners, indoor panels, decorative trim, indoor utensils, washing machine drums
Indoor environments where corrosion duty is moderate and cost control is a priority worldstainless
How to specify 304 or 430 correctly on an RFQ
When buyers only write “304” or “430,” suppliers must guess the rest, which increases bid variance. A strong RFQ typically includes:
Product form: sheet / plate / coil / strip
Thickness + tolerance framework: include allowable thickness deviation
If you need a fast tolerance reference, use: https://lyhsteel.com/dimensional-tolerance-calculator/ LYH Steel
Surface finish: 2B, BA, No.4, HL, mirror, etc.
Processing: slitting, shearing, laser cutting, polishing
LYHSteel services reference: https://lyhsteel.com/shearing/ LYH Steel
Surface finishing: https://lyhsteel.com/surface-finishing/ LYH Steel
Inspection & documentation: MTC/EN10204, PMI if needed
Packing requirement: export packing, protective film, crate/pallet
If your drawing uses gauge, convert it to mm before issuing the PO to reduce dispute risk:
https://lyhsteel.com/metal-gauge-to-thickness-calculator/ LYH Steel
For logistics planning and pieces-per-ton estimates:
https://lyhsteel.com/calculate-metal-weight/ LYH Steel
LYHSteel product links
Stainless Steel Sheet & Plate: https://lyhsteel.com/stainless-steel-sheet-plate/ LYH Steel
Stainless Steel Strip & Coil: https://lyhsteel.com/stainless-steel-strip-coil/ LYH Steel
Knowledge Center (more grade guides): https://lyhsteel.com/knowledge-center/ LYH Steel
Contact for quotation: https://lyhsteel.com/contact-us/ LYH Steel
FAQ
1) Is 430 stainless steel “food grade”?
“Food grade” depends on local regulation, surface finish, cleanability, and the specific food contact scenario. 430 is used in certain kitchen and appliance applications, but for frequent wash-down or aggressive cleaning regimes, 304 is often the safer specification baseline.
2) Which is more corrosion resistant: 304 or 430?
In general procurement practice, 304 is the more robust general-purpose choice across varied environments. 430 performs well in many indoor/mild exposures but may be less tolerant in harsher chloride-driven conditions. worldstainless+1
3) Is 304 always non-magnetic?
No. 304 is generally not magnetic when annealed, but it can become magnetic after cold working due to microstructural changes. nickelinstitute.org+1
4) Which grade is better for welded fabrication?
For most general fabrication, 304/304L is typically easier to weld reliably. Austenitic grades have recognized weldability advantages in many welded equipment builds. nickelinstitute.org
5) How do I avoid “wrong-grade” disputes with suppliers?
Specify UNS number (S30400 / S43000), thickness tolerance, finish, and required test documentation. Chemistry ranges are also published in standard references. Wikipedia