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MP 25x8x20 / N38 - ring magnet

ring magnet

Catalog no 030450

GTIN: 5906301812340

Diameter [±0,1 mm]

25 mm

internal diameter Ø [±0,1 mm]

8 mm

Height [±0,1 mm]

20 mm

Weight

80.11 g

Magnetization Direction

↑ axial

Load capacity

8.55 kg / 83.85 N

Magnetic Induction

81.51 mT

Coating

[NiCuNi] nickel

41.71 ZŁ with VAT / pcs + price for transport

33.91 ZŁ net + 23% VAT / pcs

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MP 25x8x20 / N38 - ring magnet

Specification/characteristics MP 25x8x20 / N38 - ring magnet

properties

values

Cat. no.

030450

GTIN

5906301812340

Production/Distribution

Dhit sp. z o.o.

Country of origin

Poland / China / Germany

Customs code

85059029

Diameter

25 mm [±0,1 mm]

internal diameter Ø

8 mm [±0,1 mm]

Height

20 mm [±0,1 mm]

Weight

80.11 g [±0,1 mm]

Magnetization Direction

↑ axial

Load capacity ~ ?

8.55 kg / 83.85 N

Magnetic Induction ~ ?

81.51 mT

Coating

[NiCuNi] nickel

Manufacturing Tolerance

± 0.1 mm

Magnetic properties of material N38

properties

values

units

coercivity bHc ?

860-915

kA/m

coercivity bHc ?

10.8-11.5

kOe

energy density [Min. - Max.] ?

287-303

BH max KJ/m

energy density [Min. - Max.] ?

36-38

BH max MGOe

remenance Br [Min. - Max.] ?

12.2-12.6

kGs

remenance Br [Min. - Max.] ?

1220-1260

actual internal force iHc

≥ 955

kA/m

actual internal force iHc

≥ 12

kOe

max. temperature ?

≤ 80

°C

Physical properties of NdFeB

properties

values

units

Vickers hardness

≥550

Density

≥7.4

g/cm³

Curie Temperature TC

312 - 380

°C

Curie Temperature TF

593 - 716

°F

Specific resistance

150

μΩ⋅Cm

Bending strength

250

Mpa

Compressive strength

1000~1100

Mpa

Thermal expansion parallel (∥) to orientation (M)

(3-4) x 106

°C^-1

Thermal expansion perpendicular (⊥) to orientation (M)

-(1-3) x 10-6

°C^-1

Young's modulus

1.7 x 104

kg/mm²

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Due to specific properties, neodymium element MP 25x8x20 / N38 in a ring-shaped form finds extensive use in various industries. Thanks to a powerful magnetic field of 8.55 kg, which can be described as force, they are extremely useful in applications that require strong magnetism in a relatively small area. Usage of MP 25x8x20 / N38 magnets include electrical mechanisms, generators, audio systems, and several other devices that use magnets for producing motion or storing energy. Despite their powerful strength, they have a comparatively low weight of 80.11 grams, which makes them more practical compared to bulkier alternatives.

The operation of ring magnets results from their unique atomic structure. Their properties arise from a controlled production process, including sintering and magnetization, which allows for the creation of a concentrated magnetic field in a specific direction. This makes them perfect for devices such as stepper motors or industrial robots. Additionally, ring magnets are resistant to demagnetization.

They are used in various fields of technology and industry, such as production of electronic devices, such as speakers and electric motors, the automotive industry, e.g., in the construction of electric motors, and medicine, where they are used in precision diagnostic devices. Their ability to work in high temperatures and precise magnetic field control makes them ideal for technologically advanced applications.

Their uniqueness comes from high magnetic strength, resistance to high temperatures, and precision in generating the magnetic field. Their unique ring form allows for application in devices requiring concentrated magnetic fields. Additionally, these magnets are more durable than traditional ferrite magnets, which has made them popular in advanced technologies and industrial applications.

Ring magnets perform excellently across a wide range of temperatures. Their magnetic properties remain stable, as long as the temperature does not exceed the Curie point. Compared to other types of magnets, ring magnets show greater resistance to demagnetization. For this reason, they are ideal for applications in the automotive industry, robotics, and devices requiring operation in changing or extreme environmental conditions.

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from immense strength, neodymium magnets have the following advantages:

They do not lose their power (of the magnet). After about 10 years, their power decreases by only ~1% (theoretically),
They protect against demagnetization caused by external magnetic field extremely well,
In other words, thanks to the shiny coating of nickel, gold, or silver, the element acquires an aesthetic appearance,
They have very high magnetic induction on the surface of the magnet,
Magnetic neodymium magnets are characterized by very high magnetic induction on the surface of the magnet and can operate (depending on the shape) even at temperatures of 230°C or higher...
Thanks to the flexibility in shaping or the ability to adapt to specific requirements – neodymium magnets can be produced in many variants of shapes and sizes, which amplifies their universality in usage.
Key role in advanced technologically fields – are utilized in HDD drives, electric motors, medical equipment and very advanced devices.

Disadvantages of neodymium magnets:

They are fragile when subjected to a powerful impact. If the magnets are exposed to impacts, we recommend using magnets in a protective case. The steel housing in the form of a holder protects the magnet from impacts and at the same time increases its overall strength,
High temperatures can reduce the strength of neodymium magnets. Typically, after heating above 80°C, most of them experience a permanent reduction in strength (although it is dependent on the form and size). To prevent this, we offer special magnets marked with the symbol [AH], which are highly resistant to high temperatures. They can operate even at temperatures up to 230°C, making them an ideal solution for applications requiring high-temperature operation,
Magnets exposed to a humid environment can corrode. Therefore, when using them outdoors, we suggest using waterproof magnets made of rubber, plastic, or other moisture-resistant materials,
The use of a cover - a magnetic holder is recommended due to the limited production capabilities of creating threads or complex shapes in the magnet
Potential hazard to health from tiny fragments of magnets pose a threat, when accidentally ingested, which becomes significant in the context of children's health. It's also worth noting that tiny parts of these magnets are able to hinder the diagnostic process in case of swallowing.

Safety Guidelines with Neodymium Magnets

People with pacemakers are advised to avoid neodymium magnets.

Neodymium magnets produce strong magnetic fields that can interfere with the operation of a heart pacemaker. However, if the magnetic field does not affect the device, it can damage its components or deactivate the device when it is in a magnetic field.

Neodymium magnets can become demagnetized at high temperatures.

Despite the general resilience of magnets, their ability to maintain their magnetic potency can be influenced by factors like the type of material used, the magnet's shape, and the intended purpose for which it is employed.

Magnets will attract to each other, so remember not to allow them to pinch together without control or place your fingers in their path.

If joining of neodymium magnets is not under control, then they may crumble and crack. Remember not to move them to each other or have them firmly in hands at a distance less than 10 cm.

The magnet is coated with nickel - be careful if you have an allergy.

Studies show a small percentage of people have allergies to certain metals, including nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

Neodymium magnets are over 10 times more powerful than ferrite magnets (the ones in speakers), and their strength can surprise you.

Please review the information on how to handle neodymium magnets and avoid significant harm to your body, as well as prevent unintentional damage to the magnets.

Never bring neodymium magnets close to a phone and GPS.

Neodymium magnets generate strong magnetic fields that interfere with magnetometers and compasses used in navigation, as well as internal compasses of smartphones and GPS devices.

Neodymium magnets are highly delicate, they easily break as well as can become damaged.

Neodymium magnets are characterized by considerable fragility. Neodymium magnets are made of metal and coated with a shiny nickel surface, but they are not as hard as steel. At the moment of collision between the magnets, small metal fragments can be dispersed in different directions.

Dust and powder from neodymium magnets are flammable.

Avoid drilling or mechanical processing of neodymium magnets. Once crushed into fine powder or dust, this material becomes highly flammable.

You should keep neodymium magnets at a safe distance from the wallet, computer, and TV.

Strong magnetic fields emitted by neodymium magnets can destroy magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other devices. In addition, they can damage televisions, VCRs, computer monitors, and CRT displays. Avoid placing neodymium magnets in close proximity to electronic devices.

Magnets are not toys, youngest should not play with them.

Neodymium magnets are not toys. You cannot allow them to become toys for children. In the case of small magnets, they can be swallowed and cause choking. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.

Safety rules!

In order to illustrate why neodymium magnets are so dangerous, read the article - How dangerous are strong neodymium magnets?.