NC NeoCube 5 mm kwadraty / N38 - neocube

Advantages as well as disadvantages of neodymium magnets NdFeB.

Besides their stability, neodymium magnets are valued for these benefits:

• They do not lose their even during approximately ten years – the loss of strength is only ~1% (according to tests),
• They remain magnetized despite exposure to magnetic surroundings,
• By applying a reflective layer of nickel, the element gains a modern look,
• 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 profile),
• With the option for tailored forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving design adaptation,
• Significant impact in cutting-edge sectors – they are used in computer drives, rotating machines, clinical machines along with sophisticated instruments,
• Thanks to their efficiency per volume, small magnets offer high magnetic performance, while occupying minimal space,

Disadvantages of NdFeB magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is advisable to use in a protective case. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time strengthens its overall strength,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to damp air can corrode. Therefore, for outdoor applications, we advise waterproof types made of rubber,
• Limited ability to create internal holes in the magnet – the use of a external casing is recommended,
• Possible threat from tiny pieces may arise, if ingested accidentally, which is important in the context of child safety. Moreover, miniature parts from these products have the potential to hinder health screening after being swallowed,
• Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications

Highest magnetic holding force – what affects it?

The given strength of the magnet corresponds to the optimal strength, calculated under optimal conditions, namely:

• with mild steel, used as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a polished side
• with zero air gap
• with vertical force applied
• under standard ambient temperature

What influences lifting capacity in practice

In practice, the holding capacity of a magnet is affected by these factors, arranged from the most important to the least relevant:

• 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 was assessed with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the holding force.