At One Place

Is it magnetic?

55 materials and whether a magnet sticks. Only 9 of them are ferromagnetic, which is the property a household magnet detects — everything else is either far too weakly attracted to notice or very slightly repelled.

The stainless steel trap

The most repeated magnet myth is that a magnet not sticking proves something is real stainless steel. It does not. Austenitic stainless — 304 and 316, the grades used for kitchens and marine work — is non-magnetic, while ferritic and martensitic stainless — 430, 410, most cheap cutlery — is magnetic and is still perfectly genuine stainless steel. Cold working austenitic stainless partly converts it, so the same sink can be magnetic at a pressed corner and non-magnetic in the flat.

What a magnet does stick to

Material Why
iron The archetype. Iron is what "magnetic" means in ordinary use, and it loses the property entirely above 770 °C, its Curie point.
nickel One of only three elements ferromagnetic at room temperature, along with iron and cobalt.
mild steel Strongly attracted. Plain carbon steel is the material most people mean by "magnetic metal".
high-carbon steel Strongly attracted.
tool steel Strongly attracted.
gray cast iron Strongly attracted, which is why cast iron works on an induction hob and aluminium does not.
ductile iron Strongly attracted.
wrought iron Strongly attracted.
tungsten carbide Attracted, but not because of the carbide — the cobalt binder holding the carbide grains together is ferromagnetic. A magnet sticks to a tungsten carbide ring for that reason.

Everything

Material Magnet test Why
mild steel A magnet sticks to it Strongly attracted. Plain carbon steel is the material most people mean by "magnetic metal".
aluminum A magnet does not stick to it A magnet will not stick. A magnet *moved past* aluminium induces eddy currents and drags noticeably, which is how recycling plants separate it from other metals.
water Barely — you would need a laboratory to detect it Diamagnetic. A sufficiently strong magnetic field will levitate water, and famously a live frog, which is mostly water.
copper A magnet does not stick to it Not attracted at all. A magnet dropped down a copper tube still falls slowly, which is eddy-current braking and not magnetism.
gold A magnet does not stick to it Not attracted, which is one of the quick tests against gold-plated steel.
titanium Barely — you would need a laboratory to detect it Paramagnetic — very weakly attracted, far too weakly for a fridge magnet to detect. This is why titanium implants are usually MRI-compatible.
concrete A magnet does not stick to it Not attracted — but a magnet or a metal detector finds the reinforcing bar inside it, which is how rebar scanners work.
stainless steel 304 A magnet does not stick to it A magnet does not stick to annealed 304 — it is austenitic. Cold working it, by bending or deep-drawing, converts some austenite to martensite and makes it partly magnetic, which is why a 304 sink can be magnetic at the pressed corners and not in the flat.
iron A magnet sticks to it The archetype. Iron is what "magnetic" means in ordinary use, and it loses the property entirely above 770 °C, its Curie point.
air Barely — you would need a laboratory to detect it Oxygen is paramagnetic, so air is very slightly attracted — liquid oxygen visibly sticks to a magnet.
ice Barely — you would need a laboratory to detect it Diamagnetic like liquid water.
lead A magnet does not stick to it Not attracted.
tungsten Barely — you would need a laboratory to detect it Paramagnetic and undetectable with a household magnet.
brass A magnet does not stick to it Not attracted. A magnet is the quickest way to tell brass from brass-plated steel.
pine A magnet does not stick to it Not attracted.
silver A magnet does not stick to it Not attracted.
gray cast iron A magnet sticks to it Strongly attracted, which is why cast iron works on an induction hob and aluminium does not.
diamond A magnet does not stick to it Not attracted.
high-carbon steel A magnet sticks to it Strongly attracted.
stainless steel 316 A magnet does not stick to it Austenitic like 304, and slightly less prone to becoming magnetic when cold worked because of its higher nickel content.
granite Barely — you would need a laboratory to detect it Weakly attracted where it contains magnetite, and some granites are noticeably magnetic while others are not. Geologists use exactly this to map rock types from the air.
aluminum 6061 A magnet does not stick to it Not attracted.
soda-lime glass A magnet does not stick to it Not attracted.
PTFE A magnet does not stick to it Not attracted.
marble A magnet does not stick to it Not attracted.
unidirectional carbon fibre composite A magnet does not stick to it Not attracted.
rigid PVC A magnet does not stick to it Not attracted.
fibreglass (GRP) A magnet does not stick to it Not attracted.
bronze A magnet does not stick to it Not attracted.
natural rubber A magnet does not stick to it Not attracted.
paper A magnet does not stick to it Not attracted.
mercury Barely — you would need a laboratory to detect it Diamagnetic — very slightly repelled by a strong magnet.
aluminum 7075 A magnet does not stick to it Not attracted.
tungsten carbide A magnet sticks to it Attracted, but not because of the carbide — the cobalt binder holding the carbide grains together is ferromagnetic. A magnet sticks to a tungsten carbide ring for that reason.
silicone rubber A magnet does not stick to it Not attracted.
zinc A magnet does not stick to it Not attracted.
magnesium A magnet does not stick to it Not attracted.
tool steel A magnet sticks to it Strongly attracted.
graphite Barely — you would need a laboratory to detect it Diamagnetic, and unusually strongly so — a thin flake of pyrolytic graphite will levitate above strong magnets at room temperature.
reinforced concrete A magnet does not stick to it The concrete is not, the rebar inside it is.
red oak A magnet does not stick to it Not attracted.
tin-lead solder (60/40) A magnet does not stick to it Not attracted.
platinum Barely — you would need a laboratory to detect it Paramagnetic. A magnet does not stick.
tin A magnet does not stick to it Not attracted.
Ti-6Al-4V titanium alloy Barely — you would need a laboratory to detect it Paramagnetic. Not detectable with a household magnet, which is what makes it usable for implants.
nickel A magnet sticks to it One of only three elements ferromagnetic at room temperature, along with iron and cobalt.
lead-free solder (SAC305) A magnet does not stick to it Not attracted.
chromium Barely — you would need a laboratory to detect it Antiferromagnetic at room temperature — a magnet does not stick.
silicon carbide A magnet does not stick to it Not attracted.
leather A magnet does not stick to it Not attracted.
wrought iron A magnet sticks to it Strongly attracted.
ductile iron A magnet sticks to it Strongly attracted.
Inconel 718 Barely — you would need a laboratory to detect it Essentially non-magnetic at room temperature despite being nickel-based, because the alloying suppresses ferromagnetic ordering.
pewter A magnet does not stick to it Not attracted.
Monel 400 Barely — you would need a laboratory to detect it Weakly magnetic and close to its Curie point at room temperature, so its behaviour changes noticeably with a small temperature change.

Common questions

Is stainless steel magnetic?
It depends on the grade. 304 and 316, the common kitchen and marine grades, are austenitic and non-magnetic. 430 and 410 are ferritic and martensitic and are magnetic. Both are genuinely stainless steel, so the magnet test does not tell you whether something is stainless.
Is aluminium magnetic?
No — a magnet will not stick. A magnet moved past aluminium does drag noticeably, because the changing field induces eddy currents in it. That is a different effect and is how recycling plants separate aluminium from other waste.
Which metals are magnetic?
Iron, nickel and cobalt, and alloys containing enough of them. Everything else is either paramagnetic — attracted far too weakly to notice — or diamagnetic, very slightly repelled.