Is Stainless Steel Induction Compatible? 430 vs 304 Magnetism

Yes, as long as the outside of the base is magnetic. In most induction-ready stainless cookware, that magnetism comes from a ferritic Grade 430 (18/0) layer on the bottom. ENERGY STAR estimates that induction delivers about 85% of its heating energy to the food in the pan, compared with roughly a third for gas (ENERGY STAR).

The catch is that the steel most buyers want touching food, austenitic 304 (18/8), barely reacts to a magnet. The British Stainless Steel Association puts annealed austenitic grades at a relative magnetic permeability of 1.003 to 1.05, close to the value of 1 for a vacuum (BSSA SSAS 2.81). A pan made only of 304 won’t register on an induction cooktop. As a result, manufacturers bond a magnetic stainless layer under the 304 body, usually with an aluminum or copper core in between to spread the heat.

Does Stainless Steel Work on an Induction Cooktop?

Stainless steel works on induction when the bottom of the pan is ferromagnetic, which in most stainless cookware means a Grade 430 (18/0) base layer. GE lists carbon steel, cast iron and enameled steel as compatible too, along with stainless that holds a magnet (GE Appliances). Annealed 304 on its own, however, won’t work. When a pan does couple with the cooktop, about 85% of the heating energy reaches the food, versus about a third with gas (ENERGY STAR).

Ferromagnetic means a metal is strongly attracted to a magnet and can carry a strong magnetic field itself. Why does that matter? Under the glass sits a flat coil carrying high-frequency alternating current. Its changing magnetic field induces eddy currents in the pan base, and the metal’s resistance turns those currents into heat. A ferromagnetic base helps in two ways. Its high permeability squeezes the current into a thin layer near the surface, which raises the effective resistance. In addition, the constant re-magnetizing of the steel (hysteresis) adds some heat of its own.

Electrical resistivity alone doesn’t explain it. In fact, Grade 304 has a higher resistivity than 430: 0.72 versus 0.60 Ω·mm²/m (thyssenkrupp 304, thyssenkrupp 430). The deciding factor is magnetism.

Stainless steel also spreads heat poorly. Grade 304 conducts about 16.2 W/m·K and 430 about 25 W/m·K (thyssenkrupp 304, thyssenkrupp 430), while aluminum conducts 205 W/m·K and copper 385 W/m·K (HyperPhysics). That’s why most stainless induction cookware puts an aluminum or copper layer between the magnetic outer base and the 304 cooking surface. In contrast, cast iron and carbon steel skip the core and rely on the steel itself.

Conductivity values come from different datasheets measured between 20°C and 100°C, so treat small differences as approximate.

Is Stainless Steel a Ferrous Metal? Why 304 Isn’t Magnetic

Yes, all stainless steel is a ferrous metal: iron makes up roughly 67% to 74% of Grade 304 and about 80% to 83% of Grade 430 by weight. Those figures are the iron balance left after the alloy limits in the thyssenkrupp 304 and thyssenkrupp 430 datasheets. Ferrous means iron-based, nothing more. Magnetism, however, depends on something else: how the atoms are arranged.

Grade 304 contains 17.5% to 19.5% chromium and 8.0% to 10.5% nickel (thyssenkrupp 304). Nickel stabilizes austenite, a face-centered cubic (FCC) structure that is essentially non-magnetic at room temperature (BSSA SSAS 2.81). BSSA gives annealed austenitic grades a relative permeability of 1.003 to 1.05. Ordinary ferromagnetic steels, in contrast, sit at around 14 on the same sheet.

Grade 430 has 16% to 18% chromium and no nickel (thyssenkrupp 430). Without nickel it stays ferritic, a body-centered cubic (BCC) structure that is strongly magnetic. Notably, BSSA uses 430 as its example of a “soft” ferromagnetic stainless steel.

18/8, 18/10 and 18/0 on a label: The numbers refer to chromium and nickel content. BSSA notes that 18/10 is “essentially the same” as 304 and that the “10” does not indicate a higher actual nickel content (BSSA). In other words, the 304 specification already allows 8.0% to 10.5% nickel.

18/0 is 430, the magnetic grade, and BSSA says its chromium is “nearer 17%” than 18%. When comparing quotes, ask for the grade number and a mill certificate rather than relying on the 18/x stamp. For corrosion behavior, see our guides to 18/8 stainless steel properties and 18/10 stainless steel cookware.

Sources: thyssenkrupp 304 and 430 datasheets; SSINA for 316L; BSSA SSAS 2.81 for permeability.

Thermal expansion matters once you bond different metals together. Aluminum expands about 24 × 10⁻⁶/K (HyperPhysics), more than twice as much as 430 at 10.5 × 10⁻⁶/K (thyssenkrupp 430). When a 304/aluminum/430 base heats up, the aluminum core tries to grow faster than the steel on either side, and the base can bow. Consequently, many induction pans are made with a slightly concave base when cold, so they sit flatter once hot. We cover flatness in the buyer checklist below.

Why Does a Magnet Stick to the Rim of a 304 Pot?

Because cold forming can turn part of 304’s non-magnetic austenite into magnetic martensite, especially at sharp corners and edges (BSSA SSAS 2.81). Deep drawing a pot body and rolling its rim are exactly that kind of forming. A magnet may therefore tug at the rim of an all-304 pot even though the pot won’t heat on induction. To check compatibility, test the flat center of the outside bottom.

Use a weak magnet for this test. ENERGY STAR suggests a refrigerator magnet (ENERGY STAR). In contrast, a strong neodymium magnet can pull on slightly cold-worked 304 and give you a false yes.

On a typical stainless pot, magnetism shows up in four places:

1. The flat 304 floor. It deforms very little during drawing, so it stays austenitic: μr 1.003 to 1.05 in the annealed state, per BSSA.
2. The drawn sidewall radius and rolled rim. Strain-induced martensite is the magnetic phase that heavy cold work creates here. BSSA notes this “usually occurs at sharp corners, sheared edges or machined surfaces.”
3. Weld seams. Welding filler wires are balanced to about 5%, sometimes 10%, ferrite to reduce hot cracking, so weld metal can be more magnetic than the parent sheet (BSSA SSAS 2.81). This affects welded handle brackets, not the cooking base.
4. A bonded 430 base. Fully ferritic and strongly magnetic. This is the layer that couples with the coil.

Can the rim magnetism be removed? Yes. BSSA says a full solution anneal at around 1,050 to 1,100°C with rapid cooling turns the martensite back into austenite. The grade matters as well. For example, BSSA notes that high-nickel and nitrogen-bearing austenitic grades tolerate more cold work before their permeability rises.

How Is Induction Cookware Built: Tri-Ply or Disc Base?

Stainless induction cookware is usually built one of two ways: fully clad or disc base. Fully clad pans use a bonded multi-layer sheet through the base and walls. Disc-base pots bond an aluminum or copper disc and a magnetic stainless cap under a single-layer 304 body. All-Clad’s D3 tri-ply measures about 2.6 mm thick (CenturyLife), and America’s Test Kitchen found a base around 3 mm thick worked best in its skillet tests (ATK). Vessel shape decides which build makes more sense, as we explain in our pot vs pan guide.

Fully clad cookware is formed from a laminated sheet: a 304 interior, an aluminum core and a magnetic stainless exterior, bonded before the vessel is formed. The coil heats the magnetic layer directly above it, which is mostly the base. The aluminum then carries that heat up the walls, which matters in skillets and sauté pans where food sits near the edges. In ATK’s testing, for instance, disc-bottom skillets heated erratically and scorched food around their thinner sides. You can compare layer counts in our tri-ply vs 5-ply guide.

Disc bases, on the other hand, suit tall pots. In a stockpot, the liquid moves heat up the sides, so a thick disc under a 304 body does the job. Demeyere’s Atlantis line splits its range the same way: straight-sided pots use a 7-layer InductoSeal base with a copper disc, while fry pans and conical sauté pans use 7-PlyMaterial with an aluminum core running to the edge (Demeyere). Both builds also work on gas and electric stoves. See our guides on using induction cookware on a gas stove and stainless steel cookware heat distribution types.

Induction compatibility and food-contact alloy selection need separate checks. Use our 304 vs 316 stainless steel cookware guide to compare corrosion requirements, verify the supplied grade and prepare matched quotations.

What Should OEM Buyers Specify for Induction Cookware?

Start with the base. GE recommends that induction cookware have a flat bottom at least 5 inches (127 mm) across, and a magnet must stick to it (GE Appliances). GE also notes that heat is only produced above the element ring. If the magnetic area is too small, or the base rocks on the glass, a cooktop may not detect the pan. It may also heat it unevenly. The exact error code depends on the brand.

We’ve worked in the stainless cookware export trade since 2005 and ship 20+ containers a month from our Jiangmen factory. In our experience, most RFQs lead with rim diameter, yet the coil only sees the flat magnetic base. For a custom induction line, like our 304 stainless steel pot with steamer set or stainless steel cooking pot with lid, these are the five points worth writing into the RFQ:

1. Flat magnetic base diameter, not rim diameter. For example, a pot sold as 20 cm loses width to its sidewall taper and corner radius. State the minimum flat base you need; GE’s guideline is at least 5 inches (127 mm).
2. Base flatness, cold and hot. Because the aluminum core expands more than the stainless layers, ask what cold concavity the factory builds in and how it checks that the base sits flat at cooking temperature. EN 12983-1:2023 sets general requirements for domestic cookware; ask which tests the factory runs against it and request the report.
3. Weight and gauge of the magnetic layer. GE notes that lighter-weight magnetic steel pans tend to rattle during cooking. It doesn’t recommend them. Specify the 430 layer thickness and total base thickness, then test samples on an induction hob before signing off.
4. Material verification. Ask for mill certificates for the 304 or 316L and 430 coil, and spot-check parts with an XRF analyzer or a third-party lab. A magnet can tell 430 from annealed 304, but it can’t tell you the nickel content.
5. Bond integrity. Ask how the factory checks clad or disc bonds for delamination after repeated heating, and what the pass criteria are.

Frequently Asked Questions

Conclusion

Whether a stainless pan works on induction comes down to crystal structure. Austenitic 304 (18/8) gives you a corrosion-resistant cooking surface but almost no magnetic response. Ferritic 430 (18/0) supplies the magnetism the coil needs. Meanwhile, an aluminum or copper core spreads the heat that stainless steel conducts poorly. When you check a pan at home or inspect factory samples, put a fridge magnet on the flat center of the outside base, and make sure that flat magnetic area is at least 5 inches (127 mm) across.

Reviewed by Jason Gan and the UFamcooks editorial and R&D engineering team (about us). Developing a private-label induction cookware line direct from our 10,000 m² Jiangmen factory? Explore our OEM & ODM stainless steel kitchenware manufacturing page (MOQ 500 to 5,000 pcs) or contact our engineers for base drawings, material certificates, and sample lead times.