NC NeoCube fi 5 mm kuleczki srebrne / N38 - neocube

Advantages as well as disadvantages of neodymium magnets NdFeB.

Besides their high retention, neodymium magnets are valued for these benefits:

• They retain their magnetic properties for almost 10 years – the loss is just ~1% (in theory),
• They protect against demagnetization induced by surrounding electromagnetic environments remarkably well,
• By applying a reflective layer of silver, the element gains a modern look,
• They have extremely strong magnetic induction on the surface of the magnet,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to profile),
• The ability for custom shaping as well as adaptation to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
• Wide application in new technology industries – they are utilized in computer drives, electromechanical systems, healthcare devices along with other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in tiny dimensions, which makes them useful in miniature devices

Disadvantages of rare earth magnets:

• They are prone to breaking when subjected to a strong impact. If the magnets are exposed to external force, it is advisable to use in a metal holder. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time strengthens its overall durability,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on shape). 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,
• Magnets exposed to damp air can oxidize. Therefore, for outdoor applications, we suggest waterproof types made of rubber,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing holes directly in the magnet,
• Potential hazard from tiny pieces may arise, if ingested accidentally, which is crucial in the health of young users. It should also be noted that tiny components from these assemblies can disrupt scanning after being swallowed,
• Due to the price of neodymium, their cost is relatively high,

Maximum holding power of the magnet – what affects it?

The given pulling force of the magnet corresponds to the maximum force, measured under optimal conditions, that is:

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a smooth surface
• with zero air gap
• in a perpendicular direction of force
• in normal thermal conditions

Determinants of practical lifting force of a magnet

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 was determined by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.