Stainless Steel Grade Checker
Product labels throw around 18/10, 304, 316 and 18/0 as if they settle the question of whether something is safe to cook with. They do not settle it, but they do tell you something concrete about how the metal behaves. Enter the grade from a label and this tool says what it means, how it behaves with acid and salt, and whether a magnet will tell you anything useful.
What this tool cannot do: it cannot tell you what a specific product is actually made of. A manufacturer can print 18/10 on a box and ship 18/0. The grade is a claim until it is tested, and no tool can close that gap.
Nothing is sent anywhere. The lookup runs in your browser.
What each designation means
The numbers in 18/10 are chromium and nickel content: roughly 18% chromium and 10% nickel. Chromium is what makes steel stainless at all, by forming a passive oxide layer. Nickel stabilises that layer and is what makes the 300-series resistant to acid and salt. Drop the nickel to zero and you get 18/0, which is cheap, magnetic, and quicker to pit.
| Label | Series | Chromium | Nickel | Acid & salt | Magnet | Usually found in |
|---|---|---|---|---|---|---|
| 18/0 | 430 family | 16-18% | 0% | Weakest | Sticks | Budget cutlery, flatware |
| 18/8 | 304 | 18-20% | 8-10.5% | Good | Barely | Cookware, utensils, bottles |
| 18/10 | 304 (more nickel) | 18-20% | 10-12% | Good | Barely | Premium cookware, flatware |
| 304 | 304 | 18-20% | 8-10.5% | Good | Barely | Cookware, water bottles |
| 316 / 316L | 316 | 16-18% | 10-14% | Best | Barely | Marine, medical, premium cookware |
| 430 | 430 | 16-18% | 0% | Weakest | Sticks | Appliance trim, some cutlery |
| 201 / 202 | 200-series | 15-18% | 1-4% (plus manganese) | Weak | Sticks | Budget imported ware |
Ranges are the standard designation ranges for these grades. What matters for a kitchen is almost always the same thing: how much nickel is in it. Nickel is the expensive part, so it is the first thing a cost-cutting supplier removes.
The three things a grade does not tell you
- Thickness. A 304 pan can be so thin it warps on a hot plate. Grade says nothing about gauge.
- What is on the surface. A non-stick or ceramic coating hides the metal entirely, and the coating is the part that touches your food.
- Whether the label is true. Grade claims are self-declared. The magnet test below catches the crudest substitutions, not a well-executed one.
What the magnet test actually proves
A magnet is a rough check, and it is widely misused. The 300-series (304, 316) is austenitic: in its annealed state it is essentially non-magnetic. The 400-series and 200-series are ferritic or manganese-bearing and do stick.
But cold working changes this. Deep-drawn or stamped 304 picks up a little magnetism at the bends, so a pan that grips a magnet at the corner is not automatically a fake 304. The test is only meaningful as a one-way signal: if a piece labelled 18/10 grabs a magnet hard across its whole flat surface, the label deserves a second look. It cannot prove the opposite.
Sources
- FDA - how substances that come into contact with food are regulated
- FDA - inventory of food contact substances listed in 21 CFR
- FDA - packaging and food contact substances
- ECHA - candidate list of substances of very high concern (nickel compounds)
Grade compositions are the nominal ranges published for the AISI 300 and 400 series and the EN 10088-1 designations. Stainless steel is not a single material, and the same grade name covers a range of chemistries.
Still deciding what to buy? The same nickel question runs through our cookware and dining guides, and our Editorial Policy explains the sourcing rule every claim here has to meet.
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