You're standing at your induction cooktop, a new pan in hand. You place it on the burner, turn the dial, and nothing happens. The cooktop hums, the glass surface warms, but the pan stays cold. You rotate the pan, try another zone, and still no heat. The pan looks like quality stainless steel, yet the cooktop refuses to accept it. Before you assume the stove is broken or the pan is faulty, a single question can settle the argument: will a magnet stick to this metal? The answer tells you whether the pan is ferromagnetic and therefore capable of heating on an induction burner — and it's a test you can run right there on the kitchen counter.
The Magnet on Your Countertop
Picture this: you're at your induction cooktop with a new pan. You put it on the burner, turn the dial, and nothing happens. The cooktop hums, but the pan stays cool. This is the moment when the magnet test becomes useful: induction cooktops work by generating a magnetic field that heats only ferromagnetic cookware. According to a guide on All-Clad induction compatibility, the cooktop uses a copper coil beneath the surface to create an alternating electromagnetic field. If your pan doesn't contain enough magnetic material, it simply won't heat. That's why a simple fridge magnet can tell you more than the pan's brand or price tag. Push the magnet against the bottom; if it clings, the pan is likely to work. If it slides off, you're looking at aluminum, copper, or a non-magnetic stainless steel. This quick check saves you from the frustration of a cold burner and a delayed dinner.
The reason behind the magnet test lies in how induction transfers energy. The cooktop's coil produces a rapidly alternating magnetic field. When a magnetic pan sits on the glass, that field induces electric currents—called eddy currents—inside the metal. The metal's electrical resistance converts those currents into heat, which then cooks your food. Non-magnetic materials like aluminum or copper do interact with the field, but far less efficiently, and most induction cooktops are designed to detect the magnetic response before they power up. This is why a pan's construction matters more than its looks. A tri-ply pan with an aluminum core and 18/10 stainless exterior, for example, can still be induction-compatible if it includes a magnetic stainless or iron layer. The magnet test doesn't just tell you what will stick; it tells you whether the pan can convert electricity into heat at all. It's a physics shortcut that belongs in every kitchen drawer.
Iron and Its Alloys
When people ask "what metals will a magnet stick to," the short answer is iron, nickel, cobalt, and the many alloys built around them. Steel, which is mostly iron with a small amount of carbon, is the most common magnetic metal in everyday life. Online Metals, a metals supplier, groups its inventory into alloy steel, carbon steel, and stainless steel categories—all of which rely on iron as their base. A magnet will pick up a steel screw, a cast-iron skillet, or a carbon-steel knife blade because these materials contain enough iron to align their magnetic domains. Nickel and cobalt also respond to magnets, though they're less common in household objects. They appear in specialized alloys, coins, and some rechargeable batteries. The practical rule for most people is simpler: if a metal feels heavy, looks silvery-gray, and a magnet snaps to it, you're almost certainly holding an iron-based alloy. This simple grouping explains why a magnet behaves so predictably in the real world: the iron family dominates magnetic behavior, while the rest of the periodic table stays quiet.
But not every steel behaves the same way, and that's where the question gets interesting. Consider the Damascus steel knives featured in a buyer's guide from JW SteelCrafts. They're made by forge-welding multiple steel alloys together, and they're prized for their patterned blades. A magnet sticks to them easily, because the underlying steel is still iron-rich. That contrast helps explain why the magnet test is a reliable first pass for ferrous materials. If you're sorting scrap metal in a workshop, the magnet separates steel and iron from aluminum, copper, and the red-metal alloys in a matter of seconds. The same test works on cookware, tools, and structural metal. What it doesn't do, however, is tell you whether a particular piece of steel is high-carbon or stainless. For that you need to know the alloy family, and sometimes even the crystal structure. The magnet is a phase detector, not a metallurgy lab. Still, for the question "will this work on my induction cooktop," it's the fastest and most direct answer you can get without a data sheet.
Aluminum, Copper, and the Copper Family
Now set the magnet against the other half of the metals shelf. Aluminum, copper, brass, and bronze are all true metals, but none of them will stick. A guide to brass, bronze, and copper from the machining industry explains that these three copper alloys are often confused because they look similar, yet they differ in composition: brass is copper plus zinc, bronze is copper plus tin, and pure copper is just copper. None of them contains the ferromagnetic elements—iron, nickel, or cobalt—in enough quantity to produce a magnetic response. Aluminum is even more common in cookware and outdoor gear, from foil trays to lightweight pans. Its crystalline structure and electron configuration simply don't support ferromagnetism. So when you test a piece of aluminum, the magnet slides off as if the metal weren't there. The same holds for brass fixtures and bronze sculptures. This is a useful fact for anyone who buys metal, because it instantly separates the ferrous scrap from the non-ferrous pile without chemical testing.
Why are these metals immune to magnets? The answer lies in how magnetism works at the atomic level. Ferromagnetism is a property of materials whose atoms have unpaired electrons that can align in the same direction when exposed to a magnetic field. Iron, nickel, and cobalt are the only naturally ferromagnetic elements at room temperature. Copper and aluminum have filled or paired electron shells that don't cooperate. In brass and bronze, the copper base dominates, so the alloy remains non-magnetic even when small amounts of other elements are added. A machining guide from HMaking notes that copper (C11000) is prized for electrical and thermal conductivity, not for its magnetic behavior; brass (C36000) is chosen for high-speed machining, and bronze (C93200) for wear resistance. None of those engineering decisions relies on ferromagnetism, which is exactly why a magnet test can't sort them from one another—but can tell you that none are ferrous. Understanding this mechanism prevents the common mistake of assuming that any shiny, silver-colored metal must be steel and therefore magnetic.
The Stainless Steel Exception
Here's where the rule gets a wrinkle: stainless steel. Walk into any kitchen store, and you'll see gleaming stainless pans that a magnet barely touches. The All-Clad D3 skillet, for example, is a 12-inch pan made with an 18/10 stainless steel exterior and cooking surface, bonded to a pure aluminum core. A reviewer who tested it on gas, induction, and electric cooktops gave it high marks for even heating and searing. But the 18/10 designation tells you the steel contains 18% chromium and 10% nickel—and that nickel changes its magnetic behavior. In fact, most 18/10 stainless steel is austenitic, a crystal structure that is essentially non-magnetic. So a magnet won't stick to the pan's cooking surface or its exterior. That surprises people who assume steel is steel. The pan can still be induction-compatible, but only because the manufacturer includes a magnetic layer—often a grade like 430 stainless—in the pan's construction. The magnet test alone, applied to the outside of an 18/10 pan, would give you a false "no" for induction compatibility.
The reason behind this exception is the crystal structure of the steel, not its iron content. Stainless steels are grouped by their metallurgical phase. Ferritic and martensitic stainless steels, such as grade 430, have a body-centered cubic structure that retains ferromagnetism, so magnets stick to them. Austenitic stainless steels, like the 18/10 used in All-Clad cookware, have a face-centered cubic structure that does not. The nickel in the alloy stabilizes this austenitic phase, which is why adding nickel makes the steel more corrosion-resistant but also non-magnetic. An induction cooktop guide explains that the cooktop generates an alternating magnetic field and only heats pans that can absorb that energy through magnetic hysteresis and eddy currents. If your pan's exterior is austenitic stainless, the magnetic field can't couple to it effectively. That's why cookware manufacturers often add a magnetic stainless steel or iron disc to the base. So when you test a stainless pan and the magnet doesn't stick, you're not looking at defective steel—you're looking at a different alloy phase. The magnet test is still useful, but you have to know where to test: on the base, not on the walls.
Use the Magnet Test in Real Life
Now that you know the science, here's how to apply it in your kitchen or workshop. Take a small but strong magnet—a fridge magnet or a neodymium disc works fine—and clean the surface of the metal object. Place the magnet directly against the metal and let go. If it holds firmly under its own weight, the metal is ferromagnetic. If it slides down when the surface is vertical, or if it pulls away with a light tug, the metal is non-magnetic. For cookware, test the flat base rather than the sides, because some pans use a magnetic layer only in the bottom. Also, keep in mind that a thin layer of aluminum or copper over a steel core can still allow the magnet to stick through the softer metal, so test the actual contact point. If you're sorting scrap, set up two bins—one for "sticks" and one for "doesn't stick." This one-minute check will save you from misidentifying metals that look almost identical in a pile.
Here's the reusable rule that covers almost every case you'll encounter. If the magnet sticks, the metal is an iron-based alloy: iron, steel, or a magnetic stainless variety. If the magnet doesn't stick, it's either a non-ferrous metal—aluminum, copper, brass, bronze—or an austenitic stainless steel like 18/10. For induction cookware, this rule translates directly: a pan that passes the magnet test at its base will heat on an induction cooktop; one that fails may still be compatible if it has a hidden magnetic layer, but you'll need to check the manufacturer's specs to be sure. For scrap sorting, the rule separates your ferrous pile from your non-ferrous pile, which often have different values and recycling routes. And for general curiosity, it answers the original question: what metals will a magnet stick to? The ones with iron in the right crystal structure. That's the whole rule, and it's short enough to remember the next time you're staring at a metal object and wondering whether to trust it.
Remember that cold pan on the induction cooktop? Run the magnet test on its base. If it sticks, the cooktop was the problem—perhaps the pan's base was too small or not flat. If it doesn't stick, you've found the culprit: the pan lacks the magnetic material induction needs. That's the same conclusion you'd reach if you tested an aluminum pot, a copper-bottomed saucepan, or a high-end 18/10 stainless skillet. The induction-compatible guide for All-Clad makes this clear, showing that even premium cookware must be designed for the magnetic coupling an induction burner requires. So keep a magnet in the kitchen drawer, next to the thermometer. It's the cheapest, fastest way to answer two questions at once: "Is this metal magnetic?" and "Will this pan work on my cooktop?" You don't need a lab report or a metallurgist—just a magnet and a few seconds. A quick drawer check beats a data sheet every time.
When you're faced with a metal object and you're not sure if it's magnetic, the fastest answer is still a simple magnet. A strong stick means the metal is ferrous—iron, steel, or a magnetic stainless. A weak or absent pull points to aluminum, copper, brass, bronze, or an austenitic stainless like 18/10. For cookware, test the base, not the side, because some pans hide a magnetic layer inside. For scrap, sort into two piles: sticks and doesn't. The magnet won't tell you the alloy or the grade, but it will tell you which pile to use. No app, no data sheet—just a magnet and a few seconds. That's the whole test, and it's the first tool you should reach for.
