UMP 97x40 [M8+M10] GW F300 kg / N38 - search holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They do not lose their power approximately ten years – the loss of strength is only ~1% (based on measurements),
• Their ability to resist magnetic interference from external fields is notable,
• In other words, due to the metallic gold coating, the magnet obtains an stylish appearance,
• They exhibit elevated levels of magnetic induction near the outer area of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• 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 usage potential,
• Significant impact in new technology industries – they are used in hard drives, electric drives, diagnostic apparatus and technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in compact dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a protective case. 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 strength of neodymium magnets. Typically, above 80°C, they experience permanent weakening 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 moisture can oxidize. Therefore, for outdoor applications, we suggest waterproof types made of coated materials,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing holes directly in the magnet,
• Safety concern from tiny pieces may arise, especially if swallowed, which is important in the family environments. Additionally, miniature parts from these products may interfere with diagnostics if inside the body,
• In cases of tight budgets, neodymium magnet cost may not be economically viable,

Detachment force of the magnet in optimal conditions – what contributes to it?

The given holding capacity of the magnet means the highest holding force, calculated under optimal conditions, specifically:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• of a thickness of at least 10 mm
• with a refined outer layer
• with no separation
• under perpendicular detachment force
• at room temperature

Magnet lifting force in use – key factors

The lifting capacity of a magnet is determined by in practice key elements, from primary to secondary:

• 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.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate lowers the load capacity.