NC NeoCube 5 mm kwadraty / N38 - neocube

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their tremendous pulling force, neodymium magnets offer the following advantages:

• They retain their magnetic properties for almost ten years – the loss is just ~1% (in theory),
• They remain magnetized despite exposure to magnetic surroundings,
• Because of the reflective layer of nickel, the component looks high-end,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to build),
• With the option for tailored forming and targeted design, these magnets can be produced in numerous shapes and sizes, greatly improving application potential,
• Wide application in advanced technical fields – they serve a purpose in data storage devices, rotating machines, clinical machines and high-tech tools,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is suggested to place them in a protective case. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time increases its overall durability,
• High temperatures may significantly reduce the magnetic power of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on size). 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 wet environment – during outdoor use, we recommend using encapsulated magnets, such as those made of non-metallic materials,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing holes directly in the magnet,
• Safety concern from tiny pieces may arise, if ingested accidentally, which is significant in the protection of children. Moreover, tiny components from these magnets have the potential to interfere with diagnostics if inside the body,
• Due to the price of neodymium, their cost is relatively high,

Magnetic strength at its maximum – what it depends on?

The given lifting capacity of the magnet represents the maximum lifting force, measured under optimal conditions, namely:

• with the use of low-carbon steel plate acting as a magnetic yoke
• with a thickness of minimum 10 mm
• with a polished side
• with no separation
• under perpendicular detachment force
• in normal thermal conditions

Lifting capacity in real conditions – factors

In practice, the holding capacity of a magnet is affected by these factors, in descending order of importance:

• 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.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.