304 vs 430 stainless steel: magnetic, cost and welding compared

When buyers line up 304 vs 430 stainless steel, the first surprise is the magnet. Hold one to 430 and it sticks hard. Hold it to 304 and it barely reacts. That single test points to a deeper split: 304 is an austenitic, nickel bearing grade built for food, weather and welding, while 430 is a ferritic, almost nickel free grade built for indoor trim and low cost. Both resist rust in ordinary air, but they part ways on magnetism, price and how they behave under a welding torch. This guide puts them side by side on chemistry, corrosion, cost, weldability and use, so you can pick the right one and avoid paying for 304 where 430 would do the job.

For the chloride heavy side of the same question, our 316 vs 304 stainless steel comparison covers the step up to molybdenum bearing grades, and our surface finish guide covers the shared finishes.

Microstructure diagram of austenitic 304 next to ferritic 430 stainless steel — SS304 Sheets

Table comparing chromium, nickel and carbon content of 304 and 430 stainless steel — SS430 Coils

What 304 and 430 stainless steel are

304 is the grade most people mean by stainless steel. It is austenitic, with about 18 percent chromium and 8 to 10.5 percent nickel, which is why it is called 18/8. The chromium builds a thin passive film that keeps ordinary rust away, and the nickel gives it toughness, a clean look and easy forming. You find it in sinks, countertops, handrails, food tanks and most kitchen gear.

430 is the workhorse ferritic grade. It runs about 16 to 18 percent chromium and carries almost no nickel, with carbon up to about 0.12 percent. No nickel means lower cost and a body centered cubic structure that is magnetic. It trades some corrosion resistance for price and a hard, magnetic character that suits indoor and decorative jobs. Both grades sit inside the ASTM A240 flat rolled family, and the generic grade data is documented on Wikipedia’s stainless steel page if you want to check the basics.

chemical composition: nickel is the divider

This is the table that settles most arguments. The numbers are weight percent from ASTM A240, with iron making up the balance.

Element	304	304L	430
Chromium	18.0 – 20.0	18.0 – 20.0	16.0 – 18.0
Nickel	8.0 – 10.5	8.0 – 12.0	0.75 max
Carbon	0.08 max	0.030 max	0.12 max
Manganese	2.0 max	2.0 max	1.0 max
Silicon	0.75 max	0.75 max	0.75 max
Phosphorus	0.045 max	0.045 max	0.040 max
Sulfur	0.030 max	0.030 max	0.030 max

The line that matters is nickel: 304 has it, 430 does not. That one gap drives the magnetism, most of the cost and a good part of the corrosion story. The carbon row is why 304L exists for welding, while 430 controls carbon a different way through stabilization.

Magnet held firmly to a 430 stainless steel sheet demonstrating strong magnetic pull — ASTM A240

Diagram showing ferritic 430 with magnetic domains versus non magnetic austenitic 304 — ferritic 430 steel sheet

Magnetism: the quick test that tells them apart

430 is ferritic, and ferritic stainless is ferromagnetic. A magnet clings to it firmly, which is why 430 shows up in magnetic brackets, appliance latches and parts that need to hold a magnet.

304 is austenitic. In the annealed state it is essentially non magnetic; a magnet will not stick, or will only show the faintest pull at a thin edge. The catch is cold work. Cutting, bending, drawing or heavy rolling can leave a little magnetism at the worked edges, so a magnet test is a good field clue but not proof of grade. For proof, use PMI, a positive material identification check that reads the chemistry.

This difference is the fastest way to sort the two on a job site: strong magnet pull points to 430, no pull points to 304.

Corrosion resistance: why 304 beats 430 outdoors

Pitting resistance is measured by PREN, the pitting resistance equivalent number. For these grades PREN is roughly chromium plus 3.3 times molybdenum plus 16 times nitrogen. 430 has no molybdenum and a touch less chromium, so its PREN lands around 17. 304 sits near 19.

Calificación	Approx. PREN	Behavior in service
304	18 – 20	Holds up in fresh water, mild food acid, indoor and many outdoor spots
430	16 – 17	Fine in dry indoor air, stains and rusts in moisture, salt and weather

In plain terms, 304 shrugs off kitchen acids, fresh water and most weather. 430 is happy in dry indoor air but it will stain and then rust once it meets humidity, salt spray or regular wetting. That is why 430 is an indoor and decorative grade, while 304 is the choice for food, outdoor and anything washed often. For coastal or salt heavy duty, our marine grade 316 sheet goes further still.

Cost: why 430 is the cheaper grade

430 costs far less than 304, often 30 to 50 percent lower for the same form, because it carries almost no nickel. Nickel is the expensive element in stainless, and its price on the LME sets much of 304’s cost. 430 follows chrome and stainless scrap instead, so when nickel spikes, 304 climbs while 430 barely moves and the gap between them widens.

The saving is real, but only where 430 fits the job. Use it indoors, dry and un welded, and it is the smart buy. Spec it where water, salt or welding enter the picture and the low price disappears in rust and rework. Our 2026 price guide shows the current per kg ranges for both.

Weldability: where 430 gets difficult

304 welds cleanly with TIG, MIG and stick. The main risk is sensitization on thick sections, which is why 304L exists: its low carbon keeps chromium in the mix at the weld and protects the seam. For most fabricated 304, welding is routine.

430 is harder to weld. As a ferritic grade it grows coarse grains in the heat affected zone, loses toughness there and can crack, especially on thicker sections. It also risks sensitization and sigma phase if overheated. You can weld 430, but plan for it: use 430Ti (titanium stabilized) or a 309 or 310 austenitic filler, preheat to around 150 to 200°C, keep heat input low and post heat if the spec calls for it. For structural or pressure welds, 304 is the safer, cheaper to produce choice.

If your part must be welded and hold, 304 is the grade. If it is a formed, un welded trim piece, 430 is fine.

304 stainless railing outdoors next to a 430 decorative panel used indoors — SS304 Strip

Salt spray test panel showing 430 staining faster than 304 stainless steel — 430 stainless steel pipe

Strength and heat resistance

304 is stronger at room temperature and keeps its strength and toughness down to cryogenic temperatures, which is why it serves cryogenic and food tank work. It is also the better pick for repeated heating and cooling in clean service.

430 is a little harder and wears well in dry bearing type uses, but it loses strength above about 600°C and is not for cryogenic or high heat cycling. For heat where corrosion also matters, 304 or a higher grade is the call.

Surface finishes they share

Both grades take the same mill finishes, so look and cleanability do not force the choice. 2B is the standard mill finish, No.4 is the brushed look used in kitchens and decor, BA is the bright mirror finish for visible panels, and HL is the long hairline line. Pick the finish for the job, not the grade. Our brushed sheet y cold rolled sheet pages cover the common forms, and the surface finish guide walks through 2B, No.4 and BA side by side.

Where each grade fits

Use	304	430
Kitchen counters, sinks, food contact	standard	dry use only
Outdoor, coastal, weather exposed	yes	no
Chemical, process, washdown	yes	no
Indoor decorative trim, cladding	yes	best value
Automotive trim, appliance bodies	yes	common
Magnetic brackets, shields, latches	weak or none	yes
Welded tanks, frames, structures	yes	limited
Cost driven indoor panels	ok	best value

The split shows up clearly in real parts. 304 carries the food and process side: tanks, counters, sinks and washdown frames. 430 carries the indoor and decorative side: appliance bodies, trim and panels that never meet water or weld.

Bar chart comparing 304 and 430 stainless steel price per kilogram in 2026 — 304 stainless steel bag cage

Infographic of nickel price driving 304 cost while chrome drives 430 cost — SS430 electrical casing

304 vs 430 at a glance

Property	304	430
Structure	austenitic	ferritic
Magnetic	no (annealed)	yes
Nickel	8 – 10.5%	about 0
Chromium	18 – 20%	16 – 18%
PREN	18 – 20	about 17
Relative cost	higher	30 – 50% lower
Welding	easy	needs care
Best for	food, outdoor, weld	indoor, decorative, magnetic

How to choose between 304 and 430

Use this three step check.

Will it meet water, salt, food acid or weather? If yes, choose 304. For coast or heavy chloride, move to 316.
Must it be welded or hard formed? If yes, 304 welds as routine; 430 needs a planned weld procedure.
Is it indoor, decorative, cost led and able to hold a magnet? Then 430 is the value pick.

When the job is dry, indoor and un welded, 430 saves real money. When it is wet, welded or food facing, 304 earns every cent.

How Wanzhi supplies 304 and 430

We stock 304 as sheet y plate, and 430 as sheet, all to ASTM A240 with EN 10204 3.1 mill test certificates. We cut to size, supply the shared 2B, No.4, BA and HL finishes, and mix 304 and 430 in one order so your paperwork stays in one file. For the chloride heavy jobs our 316 plate y marine grade sheet cover the step up. If you are building a tank or vessel, our 304 vs 316 brewery tank write up on the equipment side works through the grade choice, and for 18/8 naming our 18-10 stainless steel page explains the kitchen term.

Preguntas frecuentes

Is 430 stainless steel magnetic?

Yes. 430 is ferritic, so a magnet clings to it firmly. 304 is austenitic and is essentially non magnetic in the annealed state, with only a faint pull possible at cold worked edges.

Is 430 cheaper than 304?

Yes, often 30 to 50 percent lower for the same form, because 430 carries almost no nickel. Nickel sets most of 304’s price, so when nickel rises the gap between the two widens.

Can 430 be welded?

It can, but not as easily as 304. Use 430Ti or a 309 or 310 austenitic filler, preheat to about 150 to 200°C and keep heat input low. For structural or pressure welds, 304 is the safer choice.

Which is better for outdoor use?

304, by a wide margin. 430 rusts once it meets humidity, salt or regular wetting. For coastal or salt heavy duty, 316 is the better step up from 304.

Is 430 food safe?

430 is fine for dry indoor appliance use such as dishwasher interiors and bodies. For direct food contact, wet food or acidic prep, 304 is the food grade and the safer call.

How can I tell 304 from 430 on site?

A magnet is the quick field test: strong pull points to 430, no pull points to 304. For proof, use PMI, a positive material identification check that reads the chemistry and confirms the nickel.

Does 430 stainless steel rust?

It resists rust in dry indoor air, but it stains and rusts faster than 304 once moisture, salt or weather reach it. It is not the grade for wet or outdoor service.

Can I use 430 instead of 304 to cut cost?

Only when the part is indoor, dry and un welded, and does not need to hold a magnet weakly. Where water, welding or food contact enter the picture, 304 is worth the premium.

Request a quote

Tell us the grade, form, thickness and finish, and we will cut to size and ship with the MTC. For a mixed 304 and 430 order, send one inquiry and we keep it in one file.

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