UMGZ 32x18x8 [M6] GZ / N38 - magnetic holder external thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They have stable power, and over more than 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They remain magnetized despite exposure to strong external fields,
• Because of the reflective layer of silver, the component looks aesthetically refined,
• They exhibit superior levels of magnetic induction near the outer area of the magnet,
• With the right combination of magnetic alloys, they reach significant thermal stability, enabling operation at or above 230°C (depending on the form),
• Thanks to the possibility in shaping and the capability to adapt to unique requirements, neodymium magnets can be created in various configurations, which broadens their functional possibilities,
• Key role in new technology industries – they find application in hard drives, electromechanical systems, diagnostic apparatus as well as technologically developed systems,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to external force, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from breakage and additionally reinforces its overall robustness,
• 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 wet conditions can degrade. Therefore, for outdoor applications, we advise waterproof types made of rubber,
• Limited ability to create threads in the magnet – the use of a mechanical support is recommended,
• Potential hazard from tiny pieces may arise, if ingested accidentally, which is notable in the family environments. It should also be noted that small elements from these magnets might disrupt scanning when ingested,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

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

The given lifting capacity of the magnet means the maximum lifting force, calculated in the best circumstances, that is:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• of a thickness of at least 10 mm
• with a smooth surface
• with zero air gap
• with vertical force applied
• at room temperature

Lifting capacity in practice – influencing factors

The lifting capacity of a magnet is influenced by in practice key elements, according to their importance:

• Air gap between the magnet and the plate, since 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 testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet and the plate reduces the load capacity.