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neodymium magnets

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MP 20x8/4x5 / N38 - ring magnet

ring magnet

Catalog no 030333

GTIN: 5906301812272

5

Diameter [±0,1 mm]

20 mm

internal diameter Ø [±0,1 mm]

8/4 mm

Height [±0,1 mm]

5 mm

Weight

16.49 g

Magnetization Direction

↑ axial

Load capacity

1.71 kg / 16.77 N

Magnetic Induction

296.67 mT

Coating

[NiCuNi] nickel

7.75 with VAT / pcs + price for transport

6.30 ZŁ net + 23% VAT / pcs

bulk discounts:

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MP 20x8/4x5 / N38 - ring magnet

Specification/characteristics MP 20x8/4x5 / N38 - ring magnet
properties
values
Cat. no.
030333
GTIN
5906301812272
Production/Distribution
Dhit sp. z o.o.
Country of origin
Poland / China / Germany
Customs code
85059029
Diameter
20 mm [±0,1 mm]
internal diameter Ø
8/4 mm [±0,1 mm]
Height
5 mm [±0,1 mm]
Weight
16.49 g [±0,1 mm]
Magnetization Direction
↑ axial
Load capacity ~ ?
1.71 kg / 16.77 N
Magnetic Induction ~ ?
296.67 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
T
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
Hv
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

Neodymium magnets MP 20x8/4x5 / N38 in a ring form are frequently used in various industries due to their specific properties. 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 20x8/4x5 / N38 magnets include electric motors, generating systems, audio systems, and several other devices that use magnets for producing motion or storing energy. Despite their significant strength, they have a relatively low weight of 16.49 grams, which makes them more practical compared to heavier 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 makes them perfect for devices such as stepper motors or industrial robots. 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. Thanks to their temperature resistance and precision makes them indispensable in challenging industrial conditions.
Their uniqueness comes from extraordinary pulling power, ability to work in extreme conditions, and precision in generating the magnetic field. Thanks to their ring shape allows for application in devices requiring concentrated magnetic fields. Additionally, these magnets are significantly stronger and more versatile than ferrite counterparts, which has made them popular in advanced technologies and industrial applications.
Ring magnets perform excellently across a wide range of temperatures. Their magnetic properties remain stable, as long as the temperature does not exceed the Curie point. 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 as well as disadvantages of neodymium magnets NdFeB.

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

  • They do not lose their power (of the magnet). After approximately 10 years, their strength decreases by only ~1% (theoretically),
  • They protect against demagnetization caused by external magnetic sources very well,
  • In other words, thanks to the shiny coating of nickel, gold, or silver, the element acquires an aesthetic appearance,
  • They exhibit 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...
  • The ability for precise shaping and customization to specific needs – neodymium magnets can be produced in a wide range of shapes and sizes, which expands the range of their possible uses.
  • Wide application in the industry of new technologies – are utilized in hard drives, electric motors, medical apparatus or various technologically advanced devices.

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, it is suggested 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,
  • They lose power at high temperatures. Most neodymium magnets experience permanent loss of strength when heated above 80°C (depending on the shape and height). However, we also offer special magnets with high temperature resistance, up to 230°C,
  • 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,
  • Limited ability to create threads or complex shapes in the magnet - the use of a housing is recommended - magnetic holder
  • Possible danger associated with microscopic parts of magnets can be dangerous, if swallowed, which is particularly important in the context of child safety. It's also worth noting that miniscule components of these magnets can complicate diagnosis after entering the body.

Safety Precautions

Neodymium magnets can become demagnetized at high temperatures.

Under specific conditions, Neodymium magnets can lose their magnetism when subjected to high temperatures.

Magnets will attract to each other, so remember not to allow them to pinch together without control or place your fingers in their path.

If joining of neodymium magnets is not under control, then they may crumble and crack. You can't approach them to each other. At a distance less than 10 cm you should have them very strongly.

Do not bring neodymium magnets 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.

Neodymium magnets are the most powerful, most remarkable magnets on earth, and the surprising force between them can surprise you at first.

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.

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

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 damage videos, televisions, CRT computer monitors. Do not forget to keep neodymium magnets away from these electronic devices.

If you have a nickel allergy, avoid contact with neodymium magnets.

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.

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 happens because such devices have a function to deactivate them in a magnetic field.

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

Not all neodymium magnets are toys, so do not let children play with them. In such a situation, surgery is necessary to remove them. In the worst case scenario, it can result in death.

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.

Magnets made of neodymium are extremely fragile, they easily crack and can crumble.

Neodymium magnets are highly delicate, and by joining them in an uncontrolled manner, they will crack. 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.

Pay attention!

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

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tel: +48 888 99 98 98