What is the strongest magnet?
The strongest permanent magnets are neodymium magnets, with N52 being the strongest grade. But size, shape, and surface determine how much a magnet will actually hold.
Short answer: the strongest permanent magnets are neodymium magnets (NdFeB). Within neodymium, N52 is the strongest commonly available grade. But how strong a magnet holds in practice depends mainly on its size, shape, and the steel it is attached to.
Which type of magnet is the strongest?
There are four types of permanent magnets. From strongest to weakest:
| Type | Strength | Typical use |
|---|---|---|
| Neodymium (NdFeB) | Strongest | Fastening, closures, motors, technology |
| Samarium-cobalt (SmCo) | Strong, slightly less than neodymium | High temperatures |
| AlNiCo | Moderate | Sensors, measuring instruments |
| Ferrite | Weakest | Refrigerator magnets, speakers |
A neodymium magnet is about 5 to 10 times stronger than a ferrite magnet of the same size. You can read more about the difference in Neodymium, ferrite or samarium-cobalt.
Electromagnets and superconducting magnets in laboratories can be even stronger, but they only work as long as electricity flows through them. If you are looking for a loose magnet that always stays working, neodymium is the strongest.
N35, N42, N48, N52: which grade is the strongest?
The number after the N indicates the magnetic energy. The higher, the stronger the material: N52 is the strongest grade you can normally buy. The difference between N42 and N52 is about 20 to 25 percent for the same size. A larger magnet in N40 therefore often holds more than a smaller one in N52. You can find more explanation in What does N35, N42, N48 and N52 mean?
Why does one magnet hold more than another?
- Size: more material means more power. Diameter and thickness both count.
- Shape: a pot magnet has a steel pot that concentrates the force in one direction. Because of this, it holds much more than a loose magnet of the same size. Read Why are pot magnets so strong?
- Surface: the stated holding force is measured on thick, flat steel. On thin sheet metal, a painted surface, or with a gap, it is much less in practice.
- Direction: pulling straight is the hardest. Sliding sideways costs only a fraction of the force. See Holding force, pulling force and working load.
- Temperature: neodymium loses power when it gets too hot.
What are the strongest magnets in our range?
Our very strongest magnets are the large block magnets in N50. In order:
- block magnet 100 x 100 x 50 mm, N50 (approx. 350 kg);
- block magnet 80 x 80 x 40 mm, N50 (approx. 230 kg);
- block magnet 70 x 70 x 35 mm, N50 (approx. 176 kg);
- disc magnet Ø80 x 35 mm, N48, with drilled/countersunk hole (approx. 171 kg);
- pot magnet Ø75 x 18 mm with drilled/countersunk hole (approx. 107 kg).
Magnets of this size are intended for experienced users in workshops and industry. They pull with so much force towards steel and each other that they can crush fingers. Read Working safely with magnets before use.
Are you ordering the block magnet of 100 x 100 x 50 mm? Then we will call you first before we ship it.
You can find them all at Strong magnets. Not sure which one you need? Use the Magnet Advisor or calculate it with How many magnets do I need?
Is the strongest magnet also the best choice?
Not always. A magnet that is too strong is difficult to detach, can break when closing or pinch fingers, and makes a cabinet door stiff. Choose a magnet with more than enough power for your application, not the strongest one available.
Frequently asked questions
What is the strongest magnet in the world?
Of the permanent magnets, neodymium is the strongest. The very strongest magnetic fields are created with electromagnets and superconducting magnets in research laboratories, but they are not available for purchase separately.
Is an N52 magnet always stronger than an N40 magnet?
Only at the same size and shape. A large N40 pot magnet holds much more than a small N52 disc.
Are strong magnets dangerous?
They can pinch fingers, break, and are dangerous if swallowed. Keep them away from children, pacemakers, and electronics. Read Are neodymium magnets dangerous? and Working safely with magnets.
