18/10 vs 18/8 Stainless Steel: What the Nickel Means

The difference in 18/10 vs 18/8 stainless steel is two percentage points of nickel. Both markings are a recipe rather than a quality rating: 18 percent chromium first, then 10 or 8 percent nickel, with iron filling the rest. Chromium builds the corrosion-resistant surface, and the NIH Office of Dietary Supplements lists stainless steel cookware among the sources of dietary chromium. Nickel keeps the steel tough, non-magnetic and easy to polish.

Flatware and pots stamped with either ratio are usually the same steel underneath, type 304, whose published composition allows 8 to 10.5 percent nickel. A maker can aim at the top of that window and print 18/10, or sit near the bottom and print 18/8, out of one alloy family. Stainless steel is where a large share of mined nickel ends up, and the ATSDR toxicological profile for nickel names alloy production among the metal's main uses.

The short version

Here's the whole comparison before the detail. The two stamps describe the same family of steel, and the only number that moves is nickel. Neither figure says anything about pan thickness, core material or how flat the base sits on a burner, and that construction is where cooking performance actually comes from.

• Both grades hold 18 percent chromium; only the nickel share moves.
• Both stamps usually cover the same base alloy, so everyday rust resistance matches.
• A magnet that sticks hard means ferritic steel with no nickel in it.
• Look for the grade stamp on the handle or the pan base.
• For a confirmed nickel allergy, cook on pure titanium, glass or intact enamel.

What do the two numbers in 18/10 stand for?

The first figure is chromium by weight and the second is nickel by weight, both given as a share of the finished alloy. Chromium does the protective work. It reacts with oxygen in the air and forms a thin chromium oxide film across the surface, and that film reseals itself after a scratch. Nickel does something less obvious. It pushes the iron into an austenitic crystal structure, which is why a 304 pot feels dead under a magnet and takes a mirror polish. The same structure holds up better against acidic food than nickel-free steel does. Everything left over is iron with small additions of carbon, manganese and silicon.

Neither number tells you how thick the pan is, how it is layered, or how evenly it spreads heat from a gas flame. Our broader look at whether stainless steel cookware is safe covers how these metals behave over years of real use.

18/10 vs 18/8 stainless steel and that extra nickel

Two percentage points of nickel buy a brighter finish and a little more corrosion margin, and they don't change much about how dinner cooks. Both grades sit in the 300 series. Both shrug off a sink full of soapy water. The higher-nickel version polishes to a deeper shine and keeps that shine through more dishwasher cycles, which is one reason the 18/10 stamp turns up on forks and spoons far more often than on saucepans.

For a cook, construction decides performance: the thickness of the aluminum or copper core, the diameter of the flat base, whether the cladding runs all the way up the walls. A 1.5 mm disc-bottom pot and a 3 mm fully clad pot can both be labeled 18/10 and behave nothing alike on the same burner.

The nickel in either grade is alloyed into the metal and locked in the crystal lattice. It is not a coating and it cannot flake off. Small amounts can still move into food under the right conditions.

Where the nickel goes when you cook

Metal moves from a steel pan into food in very small quantities, and acidity plus long cooking times raise the amount. The NIH Office of Dietary Supplements covers the chromium half of that transfer in its fact sheet for health professionals. For nickel, the ATSDR toxicological profile identifies food as the main source of exposure for people who are not exposed at work, so a pan sits alongside everything already on the plate. A tomato sauce at a pH of roughly 4, held at a simmer for two hours, asks more of a steel surface than a steak seared for six minutes.

A few habits keep the transfer low:

• Move acidic leftovers into a glass container before they sit overnight.
• Deglaze with wine or vinegar, then get the sauce off the heat within minutes.
• Clean with a soft pad so the oxide film stays intact, and skip the steel wool.

Our post on whether titanium cookware contains nickel runs the same question through an unalloyed metal.

Which stainless grades contain no nickel?

Ferritic grades leave nickel out of the mix and stay strongly magnetic, an easy difference to feel in a cutlery drawer. Flatware marked 18/0 and pans made from type 430 belong to this group. They cost less, dent more readily and corrode faster in salty conditions, so they tend to appear as the magnetic outer skin of an induction-ready pan or as budget cutlery. At the other end of the range, type 316 adds molybdenum for better resistance to chloride pitting.

Marking	Nickel content	Magnet test	Where you see it
18/10 (type 304)	Top of the 304 range	Slides off	Forks, spoons, clad pan interiors
18/8 (type 304)	Bottom of the 304 range	Slides off	Saucepans, skillets, flatware
18/0 (type 430)	None	Sticks firmly	Budget cutlery, induction base layers
Type 316	Higher than 304, plus about 2 percent molybdenum	Slides off	Commercial pots, marine hardware
Pure titanium (Grade 1 or 2)	None	Slides off	Coating-free pans and woks

How to tell what your pan is made of

Turn the pan over, read the stamp, then check it with a magnet off the fridge door. Most clad cookware carries a mark on the base or the underside of the handle: 18/10, 18/8, 304, 316, or a line about an induction-ready bottom. A fully clad pan often pairs a nickel-bearing cooking surface with an aluminum core and a ferritic outer skin so induction coils can grip it. The magnet can stick while the food-contact layer still holds nickel.

Unmarked pans take a little more reading. You'll be judging color, weight and magnet response together. A bright, faintly bluish grey interior that stays non-magnetic is almost certainly austenitic steel. A duller grey with a warmer cast, no magnetic pull anywhere, on a pan that feels light for its size, points to titanium.

What sits under the cooking surface matters as much as the stamp on the base. We went through that layer question in our post on what is actually inside titanium cookware.

Which cookware works for a nickel allergy?

If a dermatologist has confirmed nickel sensitivity, the practical move is keeping nickel-bearing metal off the food-contact surface and off your hands. NIH StatPearls describes nickel allergy as the most common metal-related contact dermatitis, a delayed hypersensitivity that builds after repeated exposure, and it lists kitchen tools among the everyday sources alongside jewelry and watches.

For many people the trouble is skin contact: handles, tongs, cutlery held through a long meal. A smaller group reacts to dietary nickel, and for them the cooking surface counts too. Nickel-free choices include pure titanium, glass, enameled cast iron with the enamel intact, and seasoned carbon steel.

Tools deserve the same look as pans. A stainless whisk left standing in a hot acidic sauce is a long contact event for the metal and for the hand holding it. If you swap to silicone, our guide to silicone utensil heat ratings explains what the number on the handle covers. For metal tools, our titanium kitchen tools carry no nickel at all. More detail sits in our rundown of cookware for a nickel allergy.

Why titanium has no nickel ratio

Commercially pure titanium is a single element, sold as Grade 1 or Grade 2, with no chromium or nickel added to keep it stable. The metal grows its own titanium dioxide film the moment it meets air, so there's no alloy ratio to read and no sprayed layer sitting on top. Titanium melts at about 3,034°F, far above anything a home burner produces, and it weighs roughly 40 percent less than steel at the same thickness.

That changes the way it cooks. Heat crosses titanium more slowly than aluminum, so a Kaizen pan rewards a two to three minute preheat and a thin film of fat. When we sear chicken thighs in our pans, the skin lets go of the surface at about four minutes over medium-high.

Going coating-free also means there is no top layer to wear through in year three. If a phrase on the box is carrying a lot of weight in your decision, our breakdown of what 'PFAS-free' really means on a label is worth reading first.

FAQ

Is 18/10 stainless steel better than 18/8?

For cooking, no. The two share the same base alloy and behave the same way against rust in a normal kitchen. The extra nickel in 18/10 gives a brighter, longer-lasting polish, which matters most for flatware that sits on a table. Pan thickness, core material and how flat the base sits on your burner have far more effect on dinner.

Does 18/8 stainless steel rust?

It can, in small spots, under the right abuse. Chloride is the usual culprit: salt left dry on a hot surface, detergent residue baked on in a dishwasher, or soy sauce dried in a pan overnight. The damage shows as shallow pitting or orange specks that polish out with a stainless cleaner. Rinse and dry after salty cooking.

What does 18/0 stainless steel mean?

The 18 stands for chromium by weight and the 0 means there's no nickel in the alloy at all. The metal is a ferritic steel, usually type 430, and it grabs a magnet hard. You'll find it on inexpensive cutlery and on the magnetic outer layer of induction cookware. It resists corrosion less well than 304 and dents more easily.

Can you be allergic to stainless steel pans?

The reaction is to nickel in the alloy, not to steel as a material. Symptoms appear as itching, redness or small blisters where the metal touched the skin, most often from a handle, a utensil or cutlery held through a meal. A suspected allergy is worth raising with a dermatologist before you rebuild the whole kitchen.

Skipping the ratio question entirely

If reading stamps has stopped feeling worth the effort, that's an argument for a cooking surface with no alloy ratio to check in the first place. Our titanium cookware collection is built on that idea, one metal from rim to base, with no chromium and no nickel in the mix. There is no grade stamp to look up, no coating to wear through and no magnet test to run.

The habit it asks for is simple: preheat for a couple of minutes, add fat, then add food, and the surface behaves the same way from the first meal to the thousandth. Questions about a specific stamp or grade mark can go to support@kaizencookware.com.