What 18/10 stainless steel means

What the two numbers mean

The first number is the approximate percentage of chromium in the steel; the second is the percentage of nickel. Steel with at least about 10.5 percent chromium counts as stainless, because the chromium reacts with oxygen to form a thin, self-repairing film that protects the iron underneath from rust. Eighteen percent chromium gives a comfortable margin for kitchen use, where salt, acid and water are constant.

Nickel changes the crystal structure of the steel. Enough nickel makes it an austenitic steel, which is more resistant to corrosion, takes a bright polish and is not magnetic. That is why 18/10 is the usual choice for the cooking surface of good stainless pans and for flatware.

18/10 vs 18/8: is there a difference

Both 18/10 and 18/8 fall within the range of type 304 stainless steel, the standard food-grade austenitic steel. The extra nickel in 18/10 gives slightly better corrosion resistance and luster, but in daily cooking the difference is small. Many makers use the labels interchangeably, and some simply say 304 stainless.

What matters far more for cooking is how the pan is built: the thickness, and whether it has an aluminum or copper core. A thin 18/10 pan will scorch food; a thick tri-ply 18/8 pan will cook evenly. Read the stamp as a sign of the surface material, not of overall quality.

Why some stainless steel is not magnetic

Steels in the 300 series, including 18/10 and 18/8, have an austenitic structure that is not magnetic. Steels in the 400 series, including 18/0, are ferritic and magnetic. A magnet test on the base of a pan tells you which you have.

This matters for induction. An induction cooktop heats the pan through a magnetic field, so the base must contain magnetic metal. A pan made only of 18/10 steel will not work on induction. Our induction-compatible cookware page explains the test in more detail.

Note.If a magnet sticks firmly to the bottom of the pan, it will work on induction. If it barely clings or falls off, it may not heat properly.

How clad pans combine grades

Most quality clad cookware uses different steels for different layers. The interior cooking surface is usually 18/10 or 18/8 for corrosion resistance and a non-reactive surface. The core is aluminum or copper, which spreads heat quickly. The exterior is often 18/0 magnetic stainless so the pan works on induction.

So a pan described as "18/10 stainless" may well be magnetic on the outside. That is by design. Our what is clad cookware page explains tri-ply, 5-ply and copper core construction, and our best induction cookware sets guide lists pans built this way.

See induction-ready cookware sets →

What the stamp does not tell you

The stamp tells you the grade of one layer of steel. It does not tell you the thickness of the pan, how many layers it has, whether the cladding runs up the sides or only covers a disc on the bottom, how the handles are attached, or the oven limit. Those matter more for cooking and durability.

Fully clad pans, where the core runs all the way up the sides, heat more evenly than disc-bottom pans, where a thick disc is bonded only to the base and the walls are thin steel. For oven limits, check the maker's care page. On the lines we could confirm, All-Clad rates its D3, D5 and Copper Core stainless to 600°F and Made In rates its stainless clad to 800°F; see cookware oven temperature limits.

Stainless steel and acidic food

Stainless steel is considered non-reactive for everyday cooking, which is why it is the standard choice for tomato sauces, wine braises and anything with citrus. The protective chromium film keeps the surface stable, so acidic food does not pick up a metallic taste or discolor the way it can in bare iron, carbon steel or uncoated aluminum. That is a practical advantage of a stainless interior over a seasoned pan, which can lose seasoning to long acidic simmers.

For most cooks, the practical advice is simple: buy a fully clad pan with an 18/10 or 18/8 interior from a maker that publishes its materials, and care for it as described in how to cook with stainless steel pans.

Frequently asked questions

Is 18/10 stainless steel good for cookware? Yes. It is the standard material for the cooking surface of quality stainless pans. Look at the construction too: thickness and cladding matter more than the stamp.

Is 18/10 stainless steel magnetic? No. 18/10 and 18/8 are non-magnetic. Pans that work on induction usually have an 18/0 magnetic exterior layer.

Is 304 the same as 18/8? Type 304 covers steels with roughly 18 percent chromium and 8 to 10 percent nickel, so 18/8 and 18/10 both fall under it.

Does 18/10 stainless steel rust? It resists rust very well, but it can show small rust-colored spots if iron particles from steel wool or other tools are left on the surface. A stainless cleanser removes them.