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MP 25x7.5/4.5x5 / N38 - neodymium magnet

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MP 25x7.5/4.5x5 / N38 - neodymium magnet

ring magnet

catalog number 030194

5.0

external diameter Ø

25 mm [±0,1 mm]

internal diameter Ø

7.5/4.5 mm [±0,1 mm]

height

5 mm [±0,1 mm]

magnetizing direction

↑ axial

capacity ~

1.71 kg / 16.77 N

magnetic induction ~

333.60 mT / 3,336 Gs

max. temperature

≤ 80 °C

8.00 PLN gross price (including VAT) / pcs +

6.50 PLN net price + 23% VAT / pcs

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price from 1 pcs

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Call us tel: +48 888 99 98 98 or contact us through contact form on the contact page. You can check the mass as well as the appearance of neodymium magnet in our magnetic calculator force calculator

Orders placed by 2:00 PM will be shipped on the same business day.

Specification: ring magnet 25x7.5/4.5x5 / N38 ↑ axial

Characteristics: ring magnet 25x7.5/4.5x5 / N38 ↑ axial

Properties

Values

catalog number

030194

production / distribution

Dhit sp. z o.o.

country of origin

Poland / China / Germany

customs code

85059029

external diameter Ø

25 mm [±0,1 mm]

internal diameter Ø

7.5/4.5 mm [±0,1 mm]

height

5 mm [±0,1 mm]

magnetizing direction ?

↑ axial

capacity ~ ?

1.71 kg / 16.77 N

magnetic induction ~ ?

333.60 mT / 3,336 Gs

max. temperature ?

≤ 80 °C

coating type ?

[NiCuNi] nickel

weight

17.35 g

execution tolerance

± 0.1 mm

Magnetic properties of the material N38

material characteristics N38

Properties

Values

units

remenance Br [Min. - Max.] ?

12.2-12.6

kGs

remenance Br [Min. - Max.] ?

1220-1260

coercivity bHc ?

10.8-11.5

kOe

coercivity bHc ?

860-915

kA/m

actual internal force iHc

≥ 12

kOe

actual internal force iHc

≥ 955

kA/m

energy density [Min. - Max.]

36-38

BH max MGOe

energy density [Min. - Max.]

287-303

BH max KJ/m

max. temperature

≤ 80

°C

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B

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

Due to specific properties, neodymium element MP 25x7.5/4.5x5 / N38 in a ring form finds extensive use in various industries. Thanks to a powerful magnetic field of 1.71 kg, which can be described as force, they are key in applications that require strong magnetism in a compact space. Applications of MP 25x7.5/4.5x5 / N38 magnets include electrical mechanisms, generators, sound devices, and several other devices that use magnets for producing motion or energy storage. Despite their powerful strength, they have a relatively low weight of 17.35 grams, which makes them more practical compared to heavier alternatives.

Advantages and disadvantages of neodymium magnets NdFeB.

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

They do not lose their strength (of the magnet). After about 10 years, their power decreases by only ~1% (theoretically),
They are highly resistant to demagnetization by external magnetic field,
In other words, thanks to the shiny nickel, gold, or silver finish, the element gains an visually attractive appearance,
They possess very high magnetic induction on the surface of the magnet,
Magnetic neodymium magnets are characterized by hugely high magnetic induction on the surface of the magnet and can operate (depending on the form) even at temperatures of 230°C or higher...
Thanks to the flexibility in shaping and the ability to adapt to specific requirements – neodymium magnets can be produced in various forms and dimensions, which expands the range of their possible uses.
Significant importance in the industry of new technologies – find application in computer drives, electric drive mechanisms, medical apparatus or other highly developed apparatuses.

Disadvantages of neodymium magnets:

They can break as they are extremely fragile when subjected to a strong impact. If the magnets are exposed to impacts, it is suggested using magnets in a metal holder. The steel housing in the form of a holder protects the magnet from impacts and also increases its overall strength,
They lose strength at high temperatures. Most neodymium magnets experience permanent loss of strength when heated above 80°C (depending on the form and height). However, we also offer special magnets with high temperature resistance, up to 230°C,
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 or a magnetic holder is recommended due to the limited possibilities of manufacturing threads or complex shapes in the magnet
Potential hazard to health from tiny fragments of magnets pose a threat, in case of ingestion, which becomes significant in the context of children's health. It's also worth noting that miniscule components of these products can be problematic in medical diagnosis when they are in the body.

Precautions with Neodymium Magnets

Neodymium magnets can demagnetize at high temperatures.

Although magnets have shown to retain their effectiveness up to 80°C or 175°F, this temperature may vary depending on the type of material, shape, and intended use of the magnet.

People with pacemakers are advised to avoid neodymium magnets.

In the case of neodymium magnets, there is a strong magnetic field. As a result, it interferes 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 attract to each other, pinch the skin, and cause significant injuries.

Magnets will jump and contact together within a radius of several to around 10 cm from each other.

Avoid bringing neodymium magnets close to a phone or GPS.

Magnetic fields generated by neodymium magnets interfere with compasses and magnetometers used in navigation, as well as internal compasses of smartphones and GPS devices.

Neodymium magnets are the most powerful magnets ever invented. Their power can shock you.

To use magnets properly, it is best to familiarize yourself with our information beforehand. This will help you avoid significant harm to your body and the magnets themselves.

Magnets should not be treated as toys. Therefore, it is not recommended for youngest children to have access to them.

Neodymium magnets are not toys. You cannot allow them to become toys for children. In such a situation, surgery is necessary to remove them. In the worst case scenario, it can result in death.

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, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.

Keep neodymium magnets away from TV, wallet, and computer HDD.

Strong magnetic fields emitted by neodymium magnets can damage 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. You should especially avoid placing neodymium magnets near electronic devices.

Neodymium magnets are particularly delicate, which leads to damage.

In the event of a collision between two neodymium magnets, it can result in them getting chipped. They are coated with a shiny nickel plating similar to steel, but they are not as hard. In the case of a collision between two magnets, there can be a scattering of small sharp metal fragments in different directions. Protecting your eyes is essential.

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.

Please see the article - What danger lies in neodymium magnets? You will learn how to handle them properly.

MP 25x7.5/4.5x5 / N38 - neodymium magnet

ring magnet

Specification: ring magnet 25x7.5/4.5x5 / N38 ↑ axial

Magnetic properties of the material N38

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B

Recommended articles for purchase

magnetic separator 25x100 [2xM8] / N52

cylindrical magnet 35x5 / N38 ↑ axial

ring magnet 25x8x5 / N38 ↑ axial

neocube kulka fi 2 cale / N52 ↑ axial

Advantages and disadvantages of neodymium magnets NdFeB.

MP 25x7.5/4.5x5 / N38 - neodymium magnet

ring magnet

Specification: ring magnet 25x7.5/4.5x5 / N38 ↑ axial

Magnetic properties of the material N38

Physical properties of sintered neodymium magnets Nd2Fe14B

Recommended articles for purchase

magnetic separator 25x100 [2xM8] / N52

cylindrical magnet 35x5 / N38 ↑ axial

ring magnet 25x8x5 / N38 ↑ axial

neocube kulka fi 2 cale / N52 ↑ axial

Advantages and disadvantages of neodymium magnets NdFeB.

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B