Questions and answers about the composition of magnets
Permanent magnets are made from different materials depending on the type of magnet.
In our online shop, we sell permanent magnets made of neodymium-iron-boron (NdFeB), ferrite, and aluminium-nickel-cobalt (AlNiCo) in a variety of sizes and shapes.
The various magnet materials differ, amongst other things, in their composition, adhesive force, temperature resistance and corrosion resistance.
Table of Contents
What is a magnet made of?
A magnet is made of a magnetic material, the composition of which depends on the type of magnet. These magnetic materials are composed of various elements and compounds. For instance, neodymium magnets primarily contain iron and rare earth elements, whereas ferrite magnets consist mainly of iron oxide and ceramic components. The following sections detail the exact composition of the different types of magnets.What are neodymium magnets made of?
Neodymium magnets consist primarily of neodymium, iron and boron.
The magnetic material of our super-strong magnets is an alloy of neodymium, iron and boron (NdFeB).
The exact chemical formula is Nd2Fe14B.
Neodymium is the strongest material known for producing permanent magnets. Neodymium magnets differ from conventional ferrite magnets by having significantly higher remanence and coercive field strength.
Technical properties
- Grade: varies (exact values under physical magnet data)
- Magnetisation: anisotropic
- Density: 7.4 - 7.6 g/cm3
- Electrical resistance R: 1.4 - 1.6 μΩ m
- Hardness: 570 HV
- Max. working temperature: Standard: 80° C (up to 220° C possible)
- Pollutants: All products are RoHS-compliant
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What is the composition of a neodymium magnet?
The exact composition of a neodymium magnet depends on the magnet grade and the intended use. Typically, the magnetic material consists of around 65% iron and around 30% rare earth elements such as neodymium and praseodymium. Elements like dysprosium may be used in temperature-resistant magnets. The following table shows the approximate proportions of the various components in a typical neodymium magnet.| Rare earths (e.g. neodymium/praseodymium mixture) | Iron (Fe) | Boron (B) | Other metals |
| approx. 30% | approx. 65% | approx. 1 - 2% | approx. 3 - 4% |
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20 pcs. 0.24 CHF ea.*
Disc magnet Ø 3 mm, height 3 mm, holds approx. 330 g -
10 pcs. 0.44 CHF ea.*
Block magnet 6 x 4 x 2 mm, heat-resistant up to 120 °C, holds approx. 640 g -
5 pcs. 0.67 CHF ea.*
Block magnet 15 x 4 x 4 mm, heat-resistant up to 100 °C, holds approx. 1.7 kg -
10 pcs. 0.44 CHF ea.*
Cube magnet 5 mm, holds approx. 1.2 kg -
10 pcs. 0.51 CHF ea.*
Sphere magnet Ø 5 mm, holds approx. 360 g -
5 pcs. 0.75 CHF ea.*
Ring magnet Ø 10/7 mm, height 3 mm, holds approx. 400 g
What are ferrite magnets made of?
Ferrite magnets consist mainly of iron oxide and other ceramic components.
Our ferrite magnets only use strontium ferrite.
Ferrite magnets are also called ceramic magnets and are best known as refrigerator magnets. They are inexpensive to produce and resistant to heat and corrosion. The magnets are uncoated and dark grey in colour. We carry ferrite magnets in disc, block and ring shapes.
Technical properties
- Grade: Y35 (exact values under physical magnet data)
- Magnetisation: anisotropic
- Density: 5.2 g/cm3
- Electrical resistance R: 106 Ω m
- Hardness HV: 480 - 580 HV
- Max. working temperature: 250° C
- Pollutants: All products are RoHS-compliant
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What is the composition of a ferrite magnet?
Our ferrite magnets consist of around 98% strontium ferrite. The remaining approximately 2% consists, amongst other things, of aluminium silicates and calcium carbonate.| Strontium ferrite | Other components |
| approx. 98% | approx. 2% |
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20 pcs. 0.22 CHF ea.*
Disc magnet Ø 10 mm, height 3 mm, holds approx. 200 g -
10 pcs. 0.40 CHF ea.*
Block magnet 18 x 10 x 6 mm, holds approx. 630 g -
10 pcs. 0.42 CHF ea.*
Disc magnet Ø 20 mm, height 10 mm, holds approx. 1.4 kg -
5 pcs. 0.92 CHF ea.*
Block magnet 40 x 20 x 10 mm, holds approx. 2.5 kg -
10 pcs. 0.39 CHF ea.*
Ring magnet Ø 30/16 mm, height 8 mm, holds approx. 1.6 kg
What is the difference between strontium ferrite and barium ferrite?
Two different material compositions can be used for ferrite magnets: strontium ferrite and barium ferrite. In our assortment, we only carry strontium ferrite, which poses no health risks. The table below shows the key differences between strontium ferrite and barium ferrite.| Characteristic | Strontium ferrite (SrFe) | Barium ferrite (BaFe) |
| Occurrence | abundant | rare |
| Price | high | low |
| Pollutants | non-hazardous | heavy metal |
| Adhesive force | high | low |
Tip from the supermagnete team: Not sure whether you should use a neodymium or ferrite magnet for your project? In our FAQ Should I buy a ferrite or neodymium magnet?,
we compare the characteristics of both magnet types.
What are AlNiCo magnets made of?
AlNiCo magnets are made of aluminium, nickel, cobalt and iron.
The alloy we offer also contains a small amount of copper.
We sell AlNiCo magnets (chemical formula AlNiCo5) in our shop exclusively for school experiments. They generate only very low adhesive forces and lose their magnetisation relatively easily. However, it is also possible to shape this material into more complex forms, such as horseshoe magnets.
Technical properties
- Grade: LNG37
- Magnetisation: anisotropic
- Density: 7.3 g/cm3
- Max. energy product: 4.65 MGOe
- Coercive field strength bHc: 48 kA/m
- Max. working temperature: 500° C
- Pollutants: All products are RoHS-compliant
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What is the composition of an AlNiCo magnet?
The AlNiCo magnets we offer are composed of just under 50% iron. Other main components are cobalt, nickel and aluminium, as well as a small amount of copper.Composition
| Aluminium (Al) | Nickel (Ni) | Cobalt (Co) | Copper (Cu) | Iron (Fe) |
| 8.6 % | 14.5 % | 24.5 % | 3.5 % | 48.9 % |
