MPL 10x4x1.5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their remarkable field intensity, neodymium magnets offer the following advantages:

• They have unchanged lifting capacity, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• They protect against demagnetization induced by ambient magnetic fields effectively,
• Thanks to the polished finish and silver coating, they have an aesthetic appearance,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• 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 shape),
• Thanks to the flexibility in shaping and the capability to adapt to specific requirements, neodymium magnets can be created in different geometries, which broadens their application range,
• Wide application in modern technologies – they are utilized in hard drives, rotating machines, medical equipment as well as other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in compact dimensions, which allows for use in compact constructions

Disadvantages of neodymium magnets:

• They may fracture when subjected to a strong impact. If the magnets are exposed to physical collisions, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from damage and increases its overall resistance,
• They lose magnetic force at high temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the geometry and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• They rust in a damp environment. For outdoor use, we recommend using moisture-resistant magnets, such as those made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing fine shapes directly in the magnet,
• Safety concern linked to microscopic shards may arise, especially if swallowed, which is significant in the family environments. Furthermore, miniature parts from these assemblies can hinder health screening once in the system,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which may limit large-scale applications

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

The given lifting capacity of the magnet corresponds to the maximum lifting force, determined in a perfect environment, specifically:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• with no separation
• under perpendicular detachment force
• under standard ambient temperature

Determinants of lifting force in real conditions

Practical lifting force is determined by elements, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, as 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 carried out on a smooth plate of optimal thickness, under a perpendicular pulling force, however under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate reduces the load capacity.