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
bulk discounts:
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UMH 20x7x35 [M4] / N38 - magnetic holder with hook
Magnetic properties of material N38
Physical properties of NdFeB
Shopping tips
Advantages and disadvantages of neodymium magnets NdFeB.
Apart from their consistent power, neodymium magnets have these key benefits:
- Their strength remains stable, and after around ten years, it drops only by ~1% (theoretically),
- They protect against demagnetization induced by external magnetic influence very well,
- Because of the brilliant layer of gold, the component looks aesthetically refined,
- They possess strong magnetic force measurable at the magnet’s surface,
- Thanks to their high temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
- The ability for precise shaping as well as customization to specific needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
- Significant impact in advanced technical fields – they are used in data storage devices, electric drives, clinical machines or even sophisticated instruments,
- Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications
Disadvantages of rare earth magnets:
- They are prone to breaking when subjected to a strong impact. If the magnets are exposed to mechanical hits, we recommend in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from cracks and strengthens its overall durability,
- They lose strength at increased temperatures. Most neodymium magnets experience permanent reduction in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
- Due to corrosion risk in humid conditions, it is common to use sealed magnets made of rubber for outdoor use,
- Limited ability to create precision features in the magnet – the use of a magnetic holder is recommended,
- Possible threat linked to microscopic shards may arise, especially if swallowed, which is crucial in the health of young users. It should also be noted that small elements from these magnets may hinder health screening once in the system,
- Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications
Best holding force of the magnet in ideal parameters – what affects it?
The given holding capacity of the magnet represents the highest holding force, calculated in ideal conditions, specifically:
- with the use of low-carbon steel plate acting as a magnetic yoke
- having a thickness of no less than 10 millimeters
- with a refined outer layer
- in conditions of no clearance
- under perpendicular detachment force
- under standard ambient temperature
Practical lifting capacity: influencing factors
In practice, the holding capacity of a magnet is conditioned by the following aspects, from crucial to less important:
- 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 plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the holding force.
Exercise Caution with Neodymium Magnets
Dust and powder from neodymium magnets are highly flammable.
Avoid drilling or mechanical processing of neodymium magnets. Once crushed into fine powder or dust, this material becomes highly flammable.
Do not place neodymium magnets near a computer HDD, TV, and wallet.
Magnetic fields generated by neodymium magnets can damage magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other similar devices. In addition, they can damage televisions, VCRs, computer monitors, and CRT displays. You should especially avoid placing neodymium magnets near electronic devices.
Avoid contact with neodymium magnets if you have a nickel 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.
Keep neodymium magnets away from children.
Neodymium magnets are not toys. You cannot allow them to become toys for children. Small magnets pose a serious choking hazard or can attract to each other in the intestines. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.
Neodymium magnets can become demagnetized at high temperatures.
While Neodymium magnets can lose their magnetic properties 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.
Neodymium magnets are the most powerful 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 attract to each other, pinch the skin, and cause significant injuries.
Magnets will crack or alternatively crumble with uncontrolled connecting to each other. Remember not to move them to each other or hold them firmly in hands at a distance less than 10 cm.
Neodymium magnets are delicate and can easily crack as well as get damaged.
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. At the moment of collision between the magnets, tiny sharp metal pieces can be propelled in various directions at high speed. Eye protection is recommended.
Neodymium magnets should not be near 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.
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.
Caution!
To raise awareness of why neodymium magnets are so dangerous, read the article titled How very dangerous are very powerful neodymium magnets?.
