← previous

Product available shipping tomorrow

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

bulk discounts:

Need more?

price from 1 pcs

33.91 ZŁ

41.71 ZŁ

price from 20 pcs

31.88 ZŁ

39.21 ZŁ

price from 80 pcs

29.84 ZŁ

36.70 ZŁ

Carbon Footprint – environmental impact GPSR Regulation – product safety

Do you have a dilemma?

Pick up the phone and ask +48 888 99 98 98 if you prefer contact us by means of request form the contact section.
Lifting power along with form of a neodymium magnet can be analyzed on our force calculator.

Same-day processing for orders placed before 14:00.

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

Shopping tips

Produkt dostępny wysyłka jutro!

MP 25x8x20 / N38 - ring magnet

41.71 ZŁ / pcs

Produkt dostępny wysyłka jutro!

UMP 107x40 [M8+M10] GW F 400 kg / N38 - search holder

400.00 ZŁ / pcs

Produkt dostępny wysyłka jutro!

UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

6.49 ZŁ / pcs

Produkt dostępny wysyłka jutro!

MW 8x20 / N38 - cylindrical magnet

4.60 ZŁ / pcs

Due to specific properties, neodymium element MP 25x8x20 / N38 in a ring 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 very helpful in applications that require strong magnetism in a relatively small area. Usage of MP 25x8x20 / N38 magnets include electric motors, generating systems, sound devices, and numerous other devices that use magnets for generating motion or storing energy. Despite their significant strength, they have a comparatively low weight of 80.11 grams, which makes them more practical compared to bulkier alternatives.

Ring magnets work due to their 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, 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. Their ability to work in high temperatures and precise magnetic field control makes them indispensable in challenging industrial conditions.

Their uniqueness comes from high magnetic strength, resistance to high temperatures, precise control of the magnetic field. Their unique ring form allows for application in devices requiring concentrated magnetic fields. Moreover, these magnets are more durable than traditional ferrite magnets, making them an ideal choice in the automotive, electronics, and medical industries.

Ring magnets perform excellently across a wide range of temperatures. 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. 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 of class N52 and N50 is a strong and extremely powerful metallic component designed as a ring, that offers high force and versatile application. Very good price, availability, durability and universal usability.

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their immense magnetic power, neodymium magnets offer the following advantages:

Their power is maintained, and after around ten years, it drops only by ~1% (according to research),
They protect against demagnetization induced by surrounding magnetic influence remarkably well,
Thanks to the polished finish and silver coating, they have an elegant appearance,
They exhibit elevated levels of magnetic induction near the outer area of the magnet,
They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
With the option for customized forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving application potential,
Significant impact in new technology industries – they find application in computer drives, electric drives, medical equipment and high-tech tools,
Thanks to their power density, small magnets offer high magnetic performance, with minimal size,

Disadvantages of neodymium magnets:

They are fragile when subjected to a strong impact. If the magnets are exposed to external force, they should be placed in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from breakage and reinforces its overall strength,
High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on size). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
Due to corrosion risk in humid conditions, it is advisable to use sealed magnets made of synthetic coating for outdoor use,
Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing fine shapes directly in the magnet,
Safety concern related to magnet particles may arise, in case of ingestion, which is significant in the family environments. Furthermore, small elements from these assemblies can hinder health screening after being swallowed,
In cases of mass production, neodymium magnet cost may be a barrier,

Maximum lifting force for a neodymium magnet – what it depends on?

The given lifting capacity of the magnet represents the maximum lifting force, measured in ideal conditions, that is:

using a steel plate with low carbon content, acting as a magnetic circuit closure
having a thickness of no less than 10 millimeters
with a polished side
with zero air gap
under perpendicular detachment force
under standard ambient temperature

What influences lifting capacity in practice

The lifting capacity of a magnet is determined by in practice key elements, ordered from most important to least significant:

Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) can cause a drop in lifting force of up to 50%.
Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity was assessed with the use of a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.

Be Cautious with Neodymium Magnets

Make sure not to bring neodymium magnets close to the TV, wallet, and computer HDD.

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, or other devices. They can also destroy devices like video players, televisions, CRT computer monitors. Remember not to place neodymium magnets close to these electronic devices.

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

In the situation of holding a finger in the path of a neodymium magnet, in that situation, a cut or a fracture may occur.

Avoid bringing neodymium magnets close to a phone or GPS.

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.

Neodymium magnetic are characterized by their fragility, which can cause them to shatter.

Neodymium magnetic are highly delicate, and by joining them in an uncontrolled manner, they will crumble. Magnets made of neodymium are made of metal and coated with a shiny nickel, but they are not as durable 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.

Neodymium magnets are not recommended for people with pacemakers.

Neodymium magnets generate strong magnetic fields. As a result, they interfere with the operation of a pacemaker. This is because many of these devices are equipped with a function that deactivates the device in a magnetic field.

Neodymium magnets are among the most powerful magnets on Earth. The surprising 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.

Avoid contact with neodymium magnets if you have a nickel 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, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

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. Small magnets can pose a serious 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.

Neodymium magnets can become demagnetized at high temperatures.

Although magnets have demonstrated their effectiveness up to 80°C or 175°F, the temperature can vary depending on the type, shape, and intended use of the specific magnet.

Safety rules!

To raise awareness of why neodymium magnets are so dangerous, see the article titled How very dangerous are very strong neodymium magnets?.