UMH 20x7x35 [M4] / N38 - magnetic holder with hook
magnetic holder with hook
Catalog no 310425
GTIN: 5906301814542
Diameter Ø [±0,1 mm]
20 mm
Height [±0,1 mm]
35 mm
Height [±0,1 mm]
7 mm
Weight
21 g
Magnetization Direction
↑ axial
Load capacity
14.5 kg / 142.2 N
Coating
[NiCuNi] nickel
8.59 ZŁ with VAT / pcs + price for transport
6.98 ZŁ net + 23% VAT / pcs
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UMH 20x7x35 [M4] / N38 - magnetic holder with hook
Magnetic properties of material N38
Physical properties of NdFeB
Shopping tips
Advantages as well as disadvantages of neodymium magnets NdFeB.
Apart from their notable holding force, neodymium magnets have these key benefits:
- Their magnetic field is durable, and after around 10 years, it drops only by ~1% (theoretically),
- Their ability to resist magnetic interference from external fields is impressive,
- Because of the lustrous layer of nickel, the component looks aesthetically refined,
- The outer field strength of the magnet shows advanced magnetic properties,
- Neodymium magnets are known for exceptionally strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
- With the option for tailored forming and personalized design, these magnets can be produced in numerous shapes and sizes, greatly improving engineering flexibility,
- Key role in modern technologies – they are utilized in hard drives, electric motors, clinical machines or even high-tech tools,
- Compactness – despite their small size, they generate strong force, making them ideal for precision applications
Disadvantages of neodymium magnets:
- They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to mechanical hits, they should be placed in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time reinforces its overall strength,
- 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 dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
- They rust in a moist environment, especially when used outside, we recommend using waterproof magnets, such as those made of non-metallic materials,
- Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing threads directly in the magnet,
- Health risk related to magnet particles may arise, in case of ingestion, which is significant in the context of child safety. Moreover, miniature parts from these magnets might hinder health screening after being swallowed,
- Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications
Maximum lifting force for a neodymium magnet – what it depends on?
The given strength of the magnet means the optimal strength, assessed in ideal conditions, that is:
- using a steel plate with low carbon content, acting as a magnetic circuit closure
- of a thickness of at least 10 mm
- with a polished side
- in conditions of no clearance
- with vertical force applied
- in normal thermal conditions
Impact of factors on magnetic holding capacity in practice
The lifting capacity of a magnet is determined by in practice key elements, from primary to secondary:
- Air gap between the magnet and the plate, because 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 measured using a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.
Caution with Neodymium Magnets
Do not place neodymium magnets near a computer HDD, TV, and wallet.
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.
People with pacemakers are advised to avoid neodymium magnets.
Neodymium magnets generate very strong magnetic fields that can 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 made of neodymium are especially delicate, which leads to damage.
Magnets made of neodymium are delicate and will crack if allowed to collide with each other, even from a distance of a few centimeters. 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 coating is made of nickel, so be cautious 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, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.
Neodymium magnets can demagnetize at high temperatures.
While Neodymium magnets can demagnetize at high temperatures, it's important to note that the extent of this effect can vary based on factors such as the magnet's material, shape, and intended application.
It is crucial not to allow the magnets to pinch together uncontrollably or place your fingers in their path as they attract to each other.
Magnets will crack or alternatively crumble with uncontrolled connecting to each other. You can't approach them to each other. At a distance less than 10 cm you should have them extremely strongly.
It is essential to maintain neodymium magnets out of reach from children.
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.
Neodymium magnets are among the most powerful magnets on Earth. The astonishing force they generate between each other can shock you.
Make sure to review all the information we have provided. This will help you avoid harm to your body and damage to the magnets.
Dust and powder from neodymium magnets are highly flammable.
Avoid drilling or mechanical processing of neodymium magnets. If the magnet is crushed into fine powder or dust, it becomes highly flammable.
Avoid bringing neodymium magnets close to a phone or GPS.
Magnetic fields interfere with compasses and magnetometers used in navigation for air and sea transport, as well as internal compasses of smartphones and GPS devices.
Be careful!
Please see the article - What danger lies in neodymium magnets? You will learn how to handle them properly.
