XT-4 magnetyzery CO i WODY użytkowej - XT-4 magnetizer

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their consistent holding force, neodymium magnets have these key benefits:

• Their magnetic field remains stable, and after approximately 10 years, it drops only by ~1% (theoretically),
• They protect against demagnetization induced by ambient magnetic influence remarkably well,
• In other words, due to the metallic silver coating, the magnet obtains an stylish appearance,
• They have very high magnetic induction on the surface of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• With the option for fine forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving design adaptation,
• Important function in modern technologies – they are utilized in hard drives, electric drives, diagnostic apparatus or even technologically developed systems,
• Thanks to their concentrated strength, small magnets offer high magnetic performance, in miniature format,

Disadvantages of neodymium magnets:

• They are fragile when subjected to a heavy impact. If the magnets are exposed to physical collisions, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from fracture , and at the same time increases its overall strength,
• They lose power at high temperatures. Most neodymium magnets experience permanent reduction in strength when heated above 80°C (depending on the shape 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 recommended to use sealed magnets made of synthetic coating for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing complex structures directly in the magnet,
• Safety concern related to magnet particles may arise, if ingested accidentally, which is notable in the family environments. Moreover, tiny components from these devices may complicate medical imaging once in the system,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Breakaway strength of the magnet in ideal conditions – what affects it?

The given strength of the magnet corresponds to the optimal strength, assessed in ideal conditions, specifically:

• with the use of low-carbon steel plate acting as a magnetic yoke
• of a thickness of at least 10 mm
• with a smooth surface
• in conditions of no clearance
• under perpendicular detachment force
• in normal thermal conditions

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, as 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 testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as fivefold. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.