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MP 20x8/4x3 / N38 - ring magnet

ring magnet

Catalog no 030187

GTIN: 5906301812043

Diameter [±0,1 mm]

20 mm

internal diameter Ø [±0,1 mm]

8/4 mm

Height [±0,1 mm]

3 mm

Weight

9.9 g

Magnetization Direction

↑ axial

Load capacity

1.03 kg / 10.1 N

Magnetic Induction

336.17 mT

Coating

[NiCuNi] nickel

3.59 ZŁ with VAT / pcs + price for transport

2.92 ZŁ net + 23% VAT / pcs

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MP 20x8/4x3 / N38 - ring magnet

Specification/characteristics MP 20x8/4x3 / N38 - ring magnet

properties

values

Cat. no.

030187

GTIN

5906301812043

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

3 mm [±0,1 mm]

Weight

9.9 g [±0,1 mm]

Magnetization Direction

↑ axial

Load capacity ~ ?

1.03 kg / 10.1 N

Magnetic Induction ~ ?

336.17 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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Neodymium magnets MP 20x8/4x3 / N38 in a ring form are commonly used in various industries due to their unique properties. Thanks to a powerful magnetic field of 1.03 kg, which can be described as strength, they are very helpful in applications that require high magnetic power in a relatively small area. Applications of MP 20x8/4x3 / N38 magnets include electrical mechanisms, generating systems, sound devices, and many other devices that use magnets for producing motion or storing energy. Despite their significant strength, they have a relatively low weight of 9.9 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 indispensable in challenging industrial conditions.

Their uniqueness comes from high magnetic strength, resistance to high temperatures, precise control of the magnetic field. Thanks to their ring shape allows for effective use in devices such as motors or speakers. 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. They do not lose their magnetic properties, 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 neodymium magnet in classes N50 and N52 is a strong and powerful metallic component with the shape of a ring, that offers strong holding power and versatile application. Good price, availability, stability and universal usability.

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

They retain their magnetic properties for almost 10 years – the drop is just ~1% (according to analyses),
They remain magnetized despite exposure to strong external fields,
Because of the reflective layer of silver, the component looks visually appealing,
Magnetic induction on the surface of these magnets is very strong,
These magnets tolerate high temperatures, often exceeding 230°C, when properly designed (in relation to form),
With the option for customized forming and targeted design, these magnets can be produced in multiple shapes and sizes, greatly improving engineering flexibility,
Significant impact in advanced technical fields – they find application in HDDs, electromechanical systems, diagnostic apparatus and technologically developed systems,
Thanks to their efficiency per volume, small magnets offer high magnetic performance, in miniature format,

Disadvantages of rare earth magnets:

They are fragile when subjected to a powerful impact. If the magnets are exposed to shocks, we recommend in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from fracture and additionally increases its overall durability,
Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s form). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
Magnets exposed to wet conditions can corrode. Therefore, for outdoor applications, we suggest waterproof types made of rubber,
The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is difficult,
Health risk linked to microscopic shards may arise, when consumed by mistake, which is significant in the family environments. It should also be noted that miniature parts from these products can interfere with diagnostics when ingested,
Due to the price of neodymium, their cost is above average,

Handle Neodymium Magnets Carefully

Neodymium magnets can become demagnetized at high temperatures.

Although magnets are generally resilient, their ability to maintain their magnetic potency can be influenced by factors like the type of material used, the magnet's shape, and the intended purpose for which it is employed.

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, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.

Neodymium magnets are not recommended for people with pacemakers.

Neodymium magnets produce strong magnetic fields that can interfere with the operation of a heart pacemaker. Even if the magnetic field does not affect the device, it can damage its components or deactivate the entire device.

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

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.

Neodymium magnets jump and also clash mutually within a radius of several to around 10 cm from each other.

Magnets should not be treated as toys. Therefore, it is not recommended for youngest 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.

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 are over 10 times stronger than ferrite magnets (the ones in speakers), and their strength can shock 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.

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

Keep neodymium magnets away from GPS and smartphones.

Intense magnetic fields generated by neodymium magnets interfere with compasses and magnetometers used in navigation, as well as internal compasses of smartphones and GPS devices.

Safety precautions!

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