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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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price from 1 pcs
6.30 ZŁ
7.75 ZŁ
price from 600 pcs
5.92 ZŁ
7.28 ZŁ
price from 2200 pcs
5.54 ZŁ
6.82 ZŁ

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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
Polska / Chiny / Niemcy
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
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
T
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
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

Due to specific properties, MP 20x8/4x5 / N38 in a ring-shaped form finds extensive use in various industries. Thanks to a powerful magnetic field of ${capacity} kg, which can be described as force, they are key in applications that require strong magnetism in a relatively small area. Usage of MP 20x8/4x5 / N38 magnets include electrical mechanisms, generators, sound devices, and numerous 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 practical 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. Moreover, 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.
Ring magnets stand out high magnetic strength, ability to work in extreme conditions, and precision in generating 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. 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. 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.
  • Susceptibility to corrosion: They require a protective coating (e.g., nickel, zinc) to prevent rusting.
  • 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.

Safety Precautions

Neodymium magnetic are characterized by being fragile, which can cause them to crumble.

In the event of a collision between two neodymium magnets, it can result in them getting chipped. They are coated with a shiny nickel plating similar to steel, but they are not as hard. In the case of a collision between two magnets, there can be a scattering of small sharp metal fragments in different directions. Protecting your eyes is essential.

The magnet is coated with nickel - be careful 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, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

Under no circumstances should neodymium magnets be placed near a computer HDD, TV, and wallet.

Neodymium magnets produce strong magnetic fields that can destroy magnetic media such as floppy disks, video tapes, HDDs, credit cards, magnetic ID cards, cassette tapes, or other devices. They can also damage videos, televisions, CRT computer monitors. Remember not to place neodymium magnets close to these electronic devices.

Keep neodymium magnets as far away as possible from 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 primarily characterized by their significant internal force. They attract to each other, and any object that comes in their way will be affected.

Neodymium magnets will jump and touch together within a distance of several to almost 10 cm from each other.

Neodymium magnets can become demagnetized at high temperatures.

Under specific conditions, Neodymium magnets may experience demagnetization when subjected to high temperatures.

Keep neodymium magnets away from people with pacemakers.

In the case of neodymium magnets, there is a strong magnetic field. As a result, it interferes 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 over 10 times more powerful than ferrite magnets (the ones in speakers), and their power can shock 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.

  Neodymium magnets should not be around youngest children.

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 severe 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. Once crushed into fine powder or dust, this material becomes highly flammable.

In order to illustrate why neodymium magnets are so dangerous, read the article - How very dangerous are strong neodymium magnets?.

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