UMP 75x25 [M10x3] GW F200 PLATINIUM / N52 - search holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They retain their attractive force for almost 10 years – the drop is just ~1% (according to analyses),
• They remain magnetized despite exposure to magnetic noise,
• The use of a decorative nickel surface provides a refined finish,
• They possess intense magnetic force measurable at the magnet’s surface,
• 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 personalized design, these magnets can be produced in numerous shapes and sizes, greatly improving design adaptation,
• Significant impact in new technology industries – they are utilized in computer drives, rotating machines, medical equipment and other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which allows for use in small systems

Disadvantages of magnetic elements:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to shocks, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks and additionally increases its overall strength,
• High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent loss in performance (depending on height). 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 degrade. Therefore, for outdoor applications, we recommend waterproof types made of plastic,
• The use of a protective casing or external holder is recommended, since machining multi-axis shapes in neodymium magnets is not feasible,
• Health risk related to magnet particles may arise, in case of ingestion, which is significant in the context of child safety. Moreover, tiny components from these products can hinder health screening when ingested,
• In cases of mass production, neodymium magnet cost may not be economically viable,

Highest magnetic holding force – what affects it?

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

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• of a thickness of at least 10 mm
• with a refined outer layer
• with zero air gap
• in a perpendicular direction of force
• at room temperature

What influences lifting capacity in practice

The lifting capacity of a magnet is influenced by in practice the following factors, according to their importance:

• Air gap between the magnet and the plate, since 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 a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the lifting capacity.