304 vs 430: differences explained
304 vs 430: austenitic 18/8 against ferritic 17 % chromium with no nickel — one costs more and goes outdoors, the other is magnetic and stays inside.
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Overview
The question behind almost every 304-versus-430 enquiry is price, and the answer is nickel. 304 is 18 % chromium with 8 % nickel, which makes it austenitic: non-magnetic, deep-drawable, and resistant enough for food, outdoor and mildly chemical service. 430 is around 17 % chromium with no nickel at all, which makes it ferritic: magnetic, cheaper, dimensionally stable in heat — and noticeably less corrosion resistant.
Nickel is also why the price gap moves. 304 tracks the nickel market and 430 mostly does not, so the ratio between them widens and narrows through the cycle rather than sitting at a fixed percentage.
The practical dividing line is water and chlorides. Indoors, dry, wiped clean, 430 does the job and looks the same. Outdoors, near the sea, or anywhere salt and standing moisture meet the surface, 430 will stain and pit while 304 will not.
304 vs 430 side by side
| Property | 304 | 430 |
|---|---|---|
| Structure | Austenitic | Ferritic |
| EN number | 1.4301 | 1.4016 |
| Chromium | 17.5–19.5 % | 16.0–18.0 % |
| Nickel | 8.0–10.5 % | None specified |
| Max carbon | 0.07 % | 0.08 % |
| Magnetic | No in the annealed condition; slightly after heavy cold work | Yes, strongly |
| Yield Rp0.2 | 210 MPa min. (EN) | 260 MPa min. (EN) |
| Tensile Rm | 520–720 MPa | 450–600 MPa |
| Elongation | 45 % min. | 20 % min. |
| Deep drawing | Excellent — the reference material for sinks and hollowware | Limited; prone to ridging and roping |
| Work hardening | High — plan for it in tooling | Low |
| Weldability | Good with standard austenitic filler | Poor to fair — grain growth and brittleness in the HAZ |
| Thermal expansion | ≈ 17 × 10⁻⁶ /K | ≈ 10.5 × 10⁻⁶ /K — closer to carbon steel |
| Corrosion, indoor dry | Excellent | Good |
| Corrosion, outdoor / coastal | Good to fair; 316 for marine | Poor — will tea-stain and pit |
| Chloride tolerance | Moderate | Low |
| Typical uses | Food plant, sinks, façades, tanks, handrail | Appliance panels, trim, indoor cladding, exhaust parts |
| ASTM designation | A240 Type 304 | A240 Type 430 |
| Price driver | Nickel — moves with LME nickel | Chromium and scrap only |
| Typical price | Reference; the benchmark stainless price | Roughly 55–70 % of 304, widening when nickel rises |
Which should you choose?
430 where it will stay dry and be seen; 304 where it will get wet and has to last. In an appliance panel, a lift interior, indoor trim or a decorative sheet, 430 is the correct commercial choice and spending on 304 buys nothing visible. As soon as the part faces weather, handles food and cleaning chemicals, gets welded into a fabrication, or has to be deep drawn, 304 stops being the expensive option and starts being the only one that works.
If the environment is coastal or chlorinated, neither is the answer — that is 316 territory.
- Outdoor exposure, rain, condensation or wash-down
- Food, drink and pharmaceutical contact surfaces
- Deep-drawn shapes: sinks, bowls, vessel heads
- Welded fabrications that will not be post-treated
- Anywhere the surface will be cleaned with chlorides or acids
- Indoor dry service: appliance fronts, panels, lift interiors, trim
- Parts where magnetic attachment is wanted rather than a defect
- Applications with thermal cycling, where lower expansion beats higher strength
- Cost-driven decorative sheet in large volume
- Exhaust and heat-shield components where ferritic behaviour is preferred
Frequently asked questions
Is 430 stainless steel as good as 304?
Not for corrosion. 430 has no nickel and around 17 % chromium, which is enough for dry indoor service but not for weather, chlorides or wash-down. Indoors and dry the two are hard to tell apart; outdoors 430 tea-stains and pits while 304 does not.
Why is 430 stainless magnetic and 304 not?
Because of crystal structure. 430 is ferritic, which is magnetic; 304 is austenitic, which is not — although heavy cold work such as deep drawing can make a 304 part slightly magnetic at the formed areas. Magnetism is not a test of whether steel is stainless.
Can 430 stainless be used outdoors?
Only in sheltered, inland, low-pollution situations, and it will still stain. Anything exposed to rain, road salt or sea air should be 304 as a minimum, and 316 within a few kilometres of the coast.
Is 430 cheaper than 304?
Typically 55–70 % of the 304 price, and the ratio moves with the nickel market. 304 carries 8–10.5 % nickel, whose LME price drives the alloy surcharge; 430 has none, so its price is set by chromium and scrap.
Can 430 stainless be welded?
It can be, but it is the weak point of the grade: the heat-affected zone coarsens and loses toughness, and corrosion resistance drops at the weld. Where welded ferritic stainless is needed, a stabilised grade such as 441 or 430Ti is the better specification.
Which is better for a kitchen?
304 for anything that holds water or food — sinks, worktops, splashbacks behind a hob. 430 is perfectly adequate for appliance fronts, cabinet panels and trim, which is exactly where manufacturers use it.
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Verified against EN 10088-2:2014 · ASTM A240/A240M. Last checked: November 2026.