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

ring magnet

Catalog no 030194

GTIN: 5906301812111

Diameter [±0,1 mm]

25 mm

internal diameter Ø [±0,1 mm]

7.5/4.5 mm

Height [±0,1 mm]

5 mm

Weight

22.38 g

Magnetization Direction

↑ axial

Load capacity

1.71 kg / 16.77 N

Magnetic Induction

333.60 mT

Coating

[NiCuNi] nickel

8.00 ZŁ with VAT / pcs + price for transport

6.50 ZŁ net + 23% VAT / pcs

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

Specification/characteristics MP 25x7.5/4.5x5 / N38 - ring magnet

properties

values

Cat. no.

030194

GTIN

5906301812111

Production/Distribution

Dhit sp. z o.o.

Country of origin

Polska / Chiny / Niemcy

Customs code

85059029

Diameter

25 mm [±0,1 mm]

internal diameter Ø

7.5/4.5 mm [±0,1 mm]

Height

5 mm [±0,1 mm]

Weight

22.38 g [±0,1 mm]

Magnetization Direction

↑ axial

Load capacity ~ ?

1.71 kg / 16.77 N

Magnetic Induction ~ ?

333.60 mT

Coating

[NiCuNi] nickel

tolerancja wykonania

± 0.1 mm

Magnetic properties of material 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 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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Neodymium magnets MP 25x7.5/4.5x5 / N38 in a ring-shaped form are frequently used in various industries due to their unique properties. Thanks to a powerful magnetic field of ${capacity} kg, which can be described as lifting capacity, they are very helpful in applications that require strong magnetism in a compact space. Usage of MP 25x7.5/4.5x5 / N38 magnets include electrical mechanisms, generating systems, audio systems, and several other devices that use magnets for generating motion or storing energy. Despite their powerful strength, they have a relatively low weight of ${weight} grams, which makes them more convenient to use compared to bulkier alternatives.

Ring magnets work due to their atomic structure. In the production process, neodymium atoms are arranged appropriately, which allows for the creation of a concentrated magnetic field in a specific direction. This field is ideal for applications in systems requiring motion control. Additionally, ring magnets are resistant to demagnetization.

Ring magnets have a wide range of applications in many industries, such as production of electronic devices, such as speakers and electric motors, the automotive industry, e.g., in the construction of electric motors, and medical equipment, e.g., in scanning devices. Their ability to work in high temperatures and precise magnetic field control makes them indispensable in challenging industrial conditions.

Ring magnets stand out extraordinary pulling power, ability to work in extreme conditions, precise control of the magnetic field. Thanks to their ring shape allows for effective use in devices such as motors or speakers. Additionally, these magnets are more durable than traditional ferrite magnets, which has made them popular in advanced technologies and industrial applications.

Thanks to their resistance to high temperatures, ring magnets operate reliably even in tough conditions. Their magnetic properties remain stable, until the Curie temperature is exceeded, which for neodymium magnets is around 80°C. They are more resistant to loss of magnetism than traditional ferrite magnets. For this reason, they are ideal for applications in the automotive industry, robotics, and devices requiring operation in changing or extreme environmental conditions.

Advantages and disadvantages of neodymium magnets

Neodymium magnets, also known as NdFeB magnets, are currently the strongest permanent magnets available on the market. Their exceptional magnetic properties make them suitable for various industries, technologies, and everyday life. Below are the key advantages:

Immense attractive force: Even small neodymium magnets generate a very strong magnetic field.
High coercivity: They are resistant to demagnetization by external magnetic fields.
Wide operating temperature range: Standard neodymium magnets operate up to 80°C, with special versions up to 230°C.
Variety of shapes and sizes: Available in many forms, making them easy to adapt to specific applications.
Relatively low price compared to strength: They offer the best strength-to-price ratio among all magnets.
Longevity: With proper use, they retain their magnetic properties for many years.
Versatility of applications: From electric motors to speakers, separators, toys, and jewelry.

Despite numerous advantages, neodymium magnets also have certain disadvantages to consider:

Brittleness: They are hard but brittle and prone to cracking or chipping upon impact.
Limited operating temperature for standard versions: Above the Curie temperature, they lose their magnetic properties.
Strong magnetic field can be dangerous: They can damage electronics, magnetic cards, and pose a risk of attracting metal objects with great force.
Difficulties in mechanical processing: Due to their hardness and brittleness, processing them is complex.

Precautions

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

The strong magnetic field generated by neodymium magnets can destroy magnetic media such as floppy disks, video tapes, HDDs, credit cards, magnetic ID cards, cassette tapes, etc. devices. They can also destroy videos, televisions, CRT computer monitors. Remember not to place neodymium magnets close to these electronic devices.

The magnet is coated with nickel. Therefore, exercise caution 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.

Under no circumstances should neodymium magnets be brought close to GPS and smartphones.

Magnetic fields can interfere with compasses and magnetometers used in aviation and maritime navigation, as well as internal compasses of smartphones and GPS devices. There are neodymium magnets in every smartphone, for example, in the microphone and speakers.

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

Remember that neodymium magnets are not toys. Do not allow children to play with them. They can be a significant choking hazard. If multiple magnets are swallowed, they can attract to each other through the intestinal walls, causing significant injuries, and even death.

Neodymium magnets are among the strongest magnets on Earth. The astonishing force they generate between each other 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.

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.

Even though magnets have been observed to maintain their efficacy up to temperatures of 80°C or 175°F, it's essential to consider that this threshold may fluctuate depending on the magnet's type, configuration, and intended usage.

Magnets made of neodymium are noted for their fragility, which can cause them to crumble.

Neodymium magnets are characterized by significant 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.

Neodymium magnets can attract to each other, pinch the skin, and cause significant swellings.

Magnets attract each other within a distance of several to around 10 cm from each other. Remember not to place fingers between magnets or alternatively in their path when attract. Depending on how huge the neodymium magnets are, they can lead to a cut or alternatively a fracture.

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.