MW 20x18 / N38 - cylindrical magnet
cylindrical magnet
Catalog no 010040
GTIN: 5906301810391
Diameter Ø [±0,1 mm]
20 mm
Height [±0,1 mm]
18 mm
Weight
42.41 g
Magnetization Direction
↑ axial
Load capacity
19.91 kg / 195.25 N
Magnetic Induction
541.64 mT
Coating
[NiCuNi] nickel
23.54 ZŁ with VAT / pcs + price for transport
19.14 ZŁ net + 23% VAT / pcs
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MW 20x18 / N38 - cylindrical magnet
Magnetic properties of material N38
Physical properties of NdFeB
Shopping tips
Moreover, although neodymium is a component of the strongest magnets, they are susceptible to corrosion in humid environments. Therefore, they are coated with a thin layer of epoxy to increase their durability. It's worth noting that NdFeB neodymium magnets are about 13% lighter than SmCo magnets and, despite their power, are brittle, which requires care during their handling. For this reason, any mechanical processing should be done before they are magnetized.
In terms of safety, there are several recommendations regarding the use of these magnets. They should not be used in acidic, basic, organic environments or in solvents, and also in water or oil. Furthermore, they can damage data on magnetic cards and hard drives, although data deletion using a neodymium magnet is not always certain.
In terms of properties in different environments, neodymium magnets are sensitive to corrosion, especially in humid conditions. Therefore, they are often covered with coatings, such as silver, to protect them from external factors and extend their lifespan. High temperatures exceeding 130°C can cause a loss of their magnetic strength, although there are specific types of neodymium magnets that can tolerate temperatures up to 230°C.
As for risks, it is important to avoid using neodymium magnets in acidic environments, basic environments, organic or solvent environments, unless they are adequately insulated. Additionally, their use is not recommended in water, oil, or in an environment containing hydrogen, as they may lose their magnetic properties.
Advantages and disadvantages of neodymium magnets NdFeB.
In addition to their remarkable magnetic power, neodymium magnets offer the following advantages:
- They do not lose their even over nearly ten years – the loss of lifting capacity is only ~1% (theoretically),
- Their ability to resist magnetic interference from external fields is impressive,
- In other words, due to the shiny nickel coating, the magnet obtains an professional appearance,
- The outer field strength of the magnet shows remarkable magnetic properties,
- Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
- The ability for precise shaping as well as adaptation to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
- Wide application in cutting-edge sectors – they serve a purpose in HDDs, electromechanical systems, clinical machines or even sophisticated instruments,
- Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which makes them useful in miniature devices
Disadvantages of neodymium magnets:
- They may fracture when subjected to a heavy impact. If the magnets are exposed to mechanical hits, it is advisable to use in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage and additionally enhances its overall resistance,
- High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on height). 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,
- They rust in a moist environment. If exposed to rain, we recommend using sealed magnets, such as those made of polymer,
- The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is difficult,
- Safety concern linked to microscopic shards may arise, if ingested accidentally, which is significant in the family environments. Additionally, minuscule fragments from these products can disrupt scanning if inside the body,
- Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications
Highest magnetic holding force – what affects it?
The given holding capacity of the magnet means the highest holding force, determined in ideal conditions, namely:
- with the use of low-carbon steel plate acting as a magnetic yoke
- of a thickness of at least 10 mm
- with a polished side
- with no separation
- with vertical force applied
- in normal thermal conditions
Magnet lifting force in use – key factors
Practical lifting force is dependent on elements, listed from the most critical to the less significant:
- Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) causes 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 testing was performed on a smooth plate of optimal thickness, under perpendicular forces, in contrast under shearing force the holding force is lower. Additionally, even a small distance {between} the magnet and the plate reduces the load capacity.
Safety Precautions
Neodymium magnets are the strongest magnets ever invented. Their strength 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.
Neodymium magnets can demagnetize at high temperatures.
Although magnets are generally resilient, their ability to retain their magnetic strength can be influenced by factors like the type of material used, the magnet's shape, and the intended purpose for which it is employed.
Never bring neodymium magnets close to a phone and GPS.
Neodymium magnets are a source of strong magnetic fields that cause interference with magnetometers and compasses used in navigation, as well as internal compasses of smartphones and GPS 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, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.
Keep neodymium magnets away from the wallet, computer, and TV.
Strong magnetic fields emitted by neodymium magnets can damage magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other devices. They can also damage televisions, VCRs, computer monitors, and CRT displays. You should especially avoid placing neodymium magnets near electronic devices.
Magnets will attract to each other, so remember not to allow them to pinch together without control or place your fingers in their path.
Magnets will crack or crumble with uncontrolled joining to each other. You can't move them to each other. At a distance less than 10 cm you should have them very firmly.
People with pacemakers are advised to avoid neodymium magnets.
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.
Magnets are not toys, children should not play with them.
Neodymium magnets are not toys. You cannot allow them to become toys for children. In such a situation, surgery is necessary to remove them. In the worst case scenario, it can result in death.
Neodymium magnets are especially delicate, which leads to damage.
Neodymium magnets are characterized by considerable 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.
Dust and powder from neodymium magnets are flammable.
Avoid drilling or mechanical processing of neodymium magnets. If the magnet is crushed into fine powder or dust, it becomes highly flammable.
Caution!
So that know how strong neodymium magnets are and why they are so dangerous, read the article - Dangerous very powerful neodymium magnets.