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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, neodymium magnet 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 lifting capacity, they are very helpful in applications that require high magnetic power in a compact space. Usage of MP 25x7.5/4.5x5 / N38 magnets include electric motors, generators, sound devices, and numerous other devices that use magnets for generating motion or energy storage. Despite their significant strength, they have a relatively low weight of 22.38 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 field is ideal for applications in systems requiring motion control. Additionally, their resistance to high temperatures and demagnetization makes them indispensable in industry.

Ring magnets have a wide range of applications in many industries, such as electronics, e.g., in the production of speakers or electric motors, automotive, where they are used in brushless electric motors, and medical equipment, e.g., in scanning devices. Thanks to their temperature resistance and precision makes them ideal for technologically advanced applications.

Ring magnets stand out extraordinary pulling power, resistance to high temperatures, and precision in generating the magnetic field. Their unique ring form allows for application in devices requiring concentrated magnetic fields. Moreover, these magnets are significantly stronger and more versatile than ferrite counterparts, making them an ideal choice in the automotive, electronics, and medical industries.

Thanks to their resistance to high temperatures, ring magnets operate reliably even in tough conditions. 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. Because of this, they are ideal for applications in the automotive industry, robotics, and devices requiring operation in changing or extreme environmental conditions.

A ring magnet N50 and N52 is a powerful and strong metallic component designed as a ring, providing high force and universal applicability. Good price, fast shipping, durability and multi-functionality.

Advantages and disadvantages of neodymium magnets NdFeB.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

They do not lose their even during nearly ten years – the loss of strength is only ~1% (based on measurements),
They remain magnetized despite exposure to strong external fields,
Because of the brilliant layer of gold, the component looks aesthetically refined,
The outer field strength of the magnet shows elevated magnetic properties,
Thanks to their high temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
The ability for precise shaping or customization to individual needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which amplifies their functionality across industries,
Key role in cutting-edge sectors – they are used in hard drives, electric drives, healthcare devices and other advanced devices,
Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of rare earth magnets:

They may fracture when subjected to a heavy impact. If the magnets are exposed to physical collisions, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time increases its overall durability,
They lose magnetic force at high temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the geometry and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
They rust in a moist environment. If exposed to rain, we recommend using sealed magnets, such as those made of rubber,
The use of a protective casing or external holder is recommended, since machining multi-axis shapes in neodymium magnets is difficult,
Possible threat linked to microscopic shards may arise, especially if swallowed, which is notable in the family environments. It should also be noted that minuscule fragments from these products can interfere with diagnostics once in the system,
Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications

Precautions

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

The strong magnetic field generated by neodymium magnets can damage magnetic media such as floppy disks, video tapes, HDDs, credit cards, magnetic ID cards, cassette tapes, etc. devices. They can also damage videos, televisions, CRT computer monitors. Do not forget to keep neodymium magnets away from these electronic devices.

Neodymium magnets can become demagnetized 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.

Keep neodymium magnets away from people with pacemakers.

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 are primarily characterized by their significant internal force. They attract to each other, and any object that comes in their way will be affected.

If have a finger between or alternatively on the path of attracting magnets, there may be a severe cut or a fracture.

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

On our website, you can find information on how to use neodymium magnets. This will help you avoid injuries and prevent damage to the magnets.

The magnet is coated with nickel. Therefore, exercise caution if you have an allergy.

Studies clearly indicate a small percentage of people who suffer from metal allergies such as 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.

Magnets made of neodymium are fragile and can easily crack and get damaged.

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. In the event of a collision between two magnets, there may be a scattering of fragments in different directions. Protecting your eyes is crucial in such a situation.

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

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

It is important to keep neodymium magnets out of reach from children.

Remember that neodymium magnets are not toys. Be cautious and make sure no child plays 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.

Dust and powder from neodymium magnets are 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.

Warning!

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