"Stainless steel" is a family, not a single material. The cooking surface of a $35 Cuisinart skillet and the cooking surface of a $300 Heritage Steel sauté pan are both legitimately stainless — but the alloys are not the same, and the differences matter for corrosion resistance, leaching behavior, and (for a small but real subset of cooks) nickel exposure.
Most cookware shoppers never read the grade. Brands stamp "18/10 stainless steel" on a box and the buyer assumes that is just the marketing version of "it is shiny and lasts forever." It is more specific than that. The numbers tell you what the alloy actually contains, which determines how it behaves on day one of cooking and on year ten of ownership. This is the explainer for what those numbers mean and which grade is in which pan.
The grade numbering decoded
Cookware-grade stainless is one of four families. The numbering convention is older than most home cooks realize, and it traces back to the American Iron and Steel Institute's grade system for austenitic and ferritic steels.
- 304 (often labeled 18/8) — approximately 18% chromium and 8% nickel by weight, with no molybdenum. The most common cooking-surface grade in home cookware. Austenitic, non-magnetic on the food-contact side. Used in Made In Stainless Clad, Cuisinart MultiClad Pro, All-Clad D3, and most consumer stainless cookware.
- 316 (often labeled 18/10) — 16-18.5% chromium, 10-14% nickel, with 2-3% molybdenum. The molybdenum is the difference. It dramatically improves pitting and crevice corrosion resistance against chlorides — the kind of attack that comes from salt, dishwasher detergent, and prolonged contact with acidic foods. Used in Demeyere Industry 5, All-Clad D5, and many European premium ranges.
- 316L — the low-carbon variant of 316 (carbon below 0.03%) with the same Cr/Ni/Mo profile. The lower carbon prevents grain-boundary carbide precipitation at welding and high-heat sensitization. Standard in marine hardware and medical implants. Some premium cookware is built from 316L specifically because the welds and bonded edges hold up longer.
- 316Ti — 316 with a small titanium stabilizer addition. AZoM notes 316Ti is used as an alternative to 316 for elevated-temperature service in the 600-900°C range and for heavy-section welding. Heritage Steel uses 316Ti on the Heritage Steel Titanium Series cooking surface.
- 18/0 (AISI 430) — roughly 16-18% chromium and effectively 0% nickel. Ferritic in microstructure, which means it is magnetic. Less corrosion-resistant than the austenitic grades, more prone to pitting in chloride environments. Almost never used as a cooking surface — its primary cookware role is the magnetic outer layer of induction-compatible clad pans, where it lets the induction coil engage. In its own right, 18/0 lives in flatware and dishwasher-safe utensils.
The two-number labels — 18/8, 18/10, 18/0 — are loose retail shorthand for chromium-and-nickel composition. The AISI numbers (304, 316, 430) are the materials-science designations and tell you more, including whether molybdenum is in the alloy.
What chromium, nickel, and molybdenum actually do
Three elements drive the differences across grades, and each one earns its place in the alloy for a specific reason.
- Chromium is what makes the steel "stainless." At concentrations above about 10.5% it forms a thin, self-healing chromium oxide (Cr₂O₃) film on the surface — a passive layer that prevents the iron underneath from oxidizing. Every cookware grade discussed here is well above that threshold, in the 16-18% range. More chromium does not linearly mean more corrosion resistance, but below the threshold the steel rusts.
- Nickel stabilizes the austenitic crystal structure. Austenite is the face-centered cubic arrangement that gives stainless its formability, ductility, and the non-magnetic shine that consumers associate with premium cookware. Without nickel, the steel reverts to a ferritic structure (which is what 18/0 is). Higher nickel also improves resistance to a broader range of corrosive environments — the trade-off is cost (nickel is the most expensive routine alloying element) and, for the small subset of nickel-sensitive consumers, more nickel in the food-contact surface.
- Molybdenum is the differentiator between 304 and 316. At 2-3% it specifically improves pitting and crevice corrosion resistance against chlorides — salt water, brines, dishwasher detergent residues, and chloride-heavy acidic foods (citrus marinades, vinegar reductions, soy-based sauces). For a home cook this matters most for two situations: long acidic simmers and dishwasher cycles. Molybdenum-bearing alloys hold up better in both.
A useful mental model: chromium is the rust-proofing, nickel is the structural shaping, molybdenum is the corrosion upgrade. The three of them in the right ratios is what turns plain steel into the alloy that holds up to thirty years of daily use.
Which grade is in which pan
Most cookware brands publish their grade somewhere — sometimes on the product page, sometimes only in technical specifications, sometimes only on request. The picture across the category we cover:
- 304 (18/8) — Made In, Cuisinart MultiClad Pro, All-Clad D3, T-fal Stainless Pro, most home stainless cookware sold under $250 a piece. Made In specifically discloses 304 (18/10) stainless on the cooking surface of their five-ply construction.
- 316 (18/10) — Demeyere Industry 5 uses 18/10 stainless (the consumer-side label for 316 in much of the European market), All-Clad D5, several restaurant-pro and European premium brands.
- 316Ti — Heritage Steel Titanium Series. The brand markets the titanium-stabilization explicitly as a metallurgical upgrade over plain 316.
- 18/0 (AISI 430) — Robert Welch flatware, Oneida flatware, the magnetic outer layer of most induction-compatible clad cookware. Almost never the cooking surface.
A pan that does not disclose its grade is most often 304. The handful of premium brands that step up to 316 or 316Ti tend to advertise it, because the alloy upgrade is part of how they justify the price.
The nickel allergy question
If you are nickel-allergic, the grade matters more than for any other shopper.
- 304 has approximately 8% nickel.
- 316 has approximately 10% nickel.
- 316Ti has approximately 10% nickel plus the titanium stabilizer. Heritage Steel's marketing positions 316Ti as lower-leaching than plain 316 — the construction is durable, the corrosion resistance is excellent, and a small titanium addition reduces sensitization. It is not, however, a nickel-free pan. The cooking surface still contains roughly the same fraction of nickel as plain 316.
- 18/0 is the only stainless grade that is functionally nickel-free, but as noted above, it is rarely available as a cooking surface.
The leaching numbers from the Kamerud 2013 study confirm what the chemistry predicts: pans with more nickel in the alloy leached more nickel into long acidic cooks, with 316 transferring more than 304 across all cycles tested. By the tenth cycle the same 126 g serving still contained an average of 88 µg of nickel — small relative to typical dietary intake, meaningful for someone with diagnosed systemic nickel reactions. The full leaching context lives in our stainless steel nickel leaching explainer.
For the roughly 17% of women and 3% of men in the United States with nickel allergy, the practical guidance is unchanged from the leaching piece: most nickel-allergic people experience contact reactions (jewelry, watch backs, belt buckles), not systemic flares from food. A smaller subset develops oral nickel sensitivity. For that group, the cleaner answer is not "find 18/0 cookware" but "step out of stainless entirely." Cast iron is a single iron alloy with no nickel. Enameled cast iron uses vitreous enamel — a glass fused to iron — as the food-contact surface, which is inert and nickel-free. Either is the right answer for a confirmed nickel allergy.
If you are uncertain whether your sensitivity is contact-only or also dietary, that is a question for an allergist, not for the cookware aisle.
The acid and salt resistance question
The molybdenum addition in 316 earns its keep when cooking turns acidic or salty for sustained periods. Pitting corrosion — small surface defects that grow over time — is the failure mode 316 resists better than 304. In practice this means:
- For a household that simmers tomato sauces, brines pork shoulder overnight, finishes a wine reduction every week, or runs the cookware through the dishwasher daily, 316 is a measurably better long-term investment.
- For a household that mostly sears proteins, sautées vegetables, and deglazes occasionally, 304 will hold up indistinguishably.
The catch for nickel-sensitive cooks: 316 leaches more nickel than 304 in the same long acidic cook. The two questions — corrosion resistance and nickel exposure — point in different directions. For most cooks, 316 is the more durable pick. For nickel-sensitive cooks doing long simmers, 304 is the better austenitic compromise — but cast iron or enameled cast iron is cleaner still.
Cost trade-offs
Pricing for the four grades is roughly:
- 304 cookware — $50-200 per piece for premium home brands (Made In, Cuisinart, All-Clad D3).
- 316 cookware — $100-400 per piece (Demeyere Industry 5, All-Clad D5).
- 316Ti cookware — $200-500 per piece (Heritage Steel Titanium Series).
- 18/0 cookware — rarely available; mostly specialty flatware.
The premium for 316 over 304 is real but not dramatic. The premium for 316Ti reflects the niche alloy plus the brand positioning more than a transformative metallurgical jump. None of these is a poor pick for everyday cooking — the differences only become legible at the long-acidic-cook and decades-of-dishwasher-cycles end of the use spectrum.
Matching grade to use case
- Most home cooks — 304 is fine. Made In Stainless Clad and Cuisinart MultiClad Pro cover the spectrum from premium to value. The leaching is small, the longevity is essentially unlimited, and the cooking experience is the standard against which other grades are judged.
- Heavy acid or salt cooking, dishwasher daily — 316. Demeyere Industry 5 is the high-end choice; All-Clad D5 is the more visible US brand at the same alloy class. The molybdenum addition is meaningful for the way you cook.
- Premium domestic, want the best alloy — 316Ti. Heritage Steel Titanium Series is the only mainstream brand using it. Honest framing: incremental improvement over 316, not transformative.
- Nickel allergy with confirmed dietary sensitivity — step out of stainless. Lodge 12-inch cast iron skillet is single-alloy iron. Le Creuset enameled cast iron is vitreous glass over iron. 100% mineral ceramic (Xtrema and similar) is a third option. None of these contains nickel.
What the grades change about the broader cookware story
The grade question is a finer-grained version of the PFAS-free cookware decision. Once you have ruled out PTFE non-stick, the remaining choice is between cast iron, ceramic-coated, and stainless. Within stainless, the grade narrows it further — and for most cooks, 304 is the right answer the first time. The 316 and 316Ti decisions are real but narrow: they help in long-acid and high-salt environments, and they cost more for the privilege.
The grade does not change the basic case for stainless over PTFE. Both 304 and 316 are durable, non-coated, induction-compatible, and dishwasher-tolerant in a way no fluoropolymer coating can match. The grade is the second-order question — the one to ask after you have already ruled out the chemistry you do not want.
For the deeper trade-off between stainless, cast iron, and ceramic, our cast iron vs ceramic vs stainless comparison walks through which category fits which kind of cook before the brand and grade decision even comes up.
