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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

Poland / China / Germany

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

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, MP 25x7.5/4.5x5 / N38 in a ring-shaped form finds extensive use in various industries. Thanks to a powerful magnetic field of 1.71 kg, which can be described as lifting capacity, they are key in applications that require high magnetic power in a relatively small area. Usage of MP 25x7.5/4.5x5 / N38 magnets include electrical mechanisms, generators, sound devices, and numerous other devices that use magnets for generating motion or energy storage. Despite their significant strength, they have a comparatively low weight of 22.38 grams, which makes them more convenient to use compared to heavier alternatives.

The operation of ring magnets results from their unique 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. Moreover, their resistance to high temperatures and demagnetization makes them indispensable in industry.

They are used in various fields of technology and industry, such as electronics, e.g., in the production of speakers or 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 ideal for technologically advanced applications.

Their uniqueness comes from extraordinary pulling power, resistance to high temperatures, and precision in generating 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.

Ring magnets perform excellently across a wide range of temperatures. They do not lose their magnetic properties, until the Curie temperature is exceeded, which for neodymium magnets is around 80°C. Compared to other types of magnets, ring magnets show greater resistance to demagnetization. Because of this, 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.

In addition to immense strength, neodymium magnets have the following advantages:

They do not lose strength over time. After about 10 years, their strength decreases by only ~1% (theoretically),
They are extremely resistant to demagnetization by external magnetic sources,
In other words, thanks to the shiny nickel, gold, or silver finish, the element gains an visually attractive appearance,
They have 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...
Due to the option of accurate forming or adaptation to individual needs – neodymium magnets can be produced in various forms and dimensions, which amplifies their universality in usage.
Wide application in modern technologies – are used in HDD drives, electric drive mechanisms, medical apparatus and other highly developed apparatuses.

Disadvantages of neodymium magnets:

They are prone to breaking as they are fragile when subjected to a powerful impact. If the magnets are exposed to impacts, we recommend using magnets in a steel housing. The steel housing in the form of a holder protects the magnet from impacts and simultaneously 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 loss 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,
Due to their susceptibility to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic, or other moisture-resistant materials when using them outdoors,
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
Possible danger associated with microscopic parts of magnets pose a threat, when accidentally ingested, which is crucial in the context of children's health. Furthermore, miniscule components of these products are able to hinder the diagnostic process after entering the body.

Exercise Caution with Neodymium Magnets

People with pacemakers are advised to avoid neodymium magnets.

Neodymium magnets generate very strong magnetic fields that can interfere with the operation of a pacemaker. This happens because such devices have a function to deactivate them in a magnetic field.

Keep neodymium magnets as far away as possible from GPS and smartphones.

Neodymium magnets are a source of intense magnetic fields that cause interference with magnetometers and compasses used in navigation, as well as internal compasses of smartphones and GPS devices.

Dust and powder from neodymium magnets are highly flammable.

Do not attempt to drill into neodymium magnets. Mechanical processing is also not recommended. If the magnet is crushed into fine powder or dust, it becomes highly flammable.

Magnets made of neodymium are especially delicate, which leads to shattering.

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 connection between the magnets, small metal fragments can be dispersed in different directions.

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

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. You should especially avoid placing neodymium magnets near electronic devices.

Avoid contact with neodymium magnets if you have a nickel 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.

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

Neodymium magnets can demagnetize at high temperatures.

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

Maintain neodymium magnets far from youngest children.

Neodymium magnets are not toys. You cannot allow them to become toys for children. Small magnets pose a serious choking hazard or can attract to each other in the intestines. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.

Neodymium Magnets can attract to each other due to their immense internal force, causing the skin and other body parts to get pinched and resulting in significant injuries.

Magnets may crack or alternatively crumble with careless joining to each other. Remember not to move them to each other or hold them firmly in hands at a distance less than 10 cm.

Caution!

To illustrate why neodymium magnets are so dangerous, see the article - How dangerous are powerful neodymium magnets?.