UMGB 107x40 [M8+M10] GW F400 +Lina GOBLIN / N38 - goblin magnetic holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after ten years, the decline in efficiency is only ~1% (based on calculations),
• They protect against demagnetization induced by ambient magnetic influence very well,
• In other words, due to the shiny gold coating, the magnet obtains an stylish appearance,
• Magnetic induction on the surface of these magnets is impressively powerful,
• With the right combination of compounds, they reach significant thermal stability, enabling operation at or above 230°C (depending on the design),
• With the option for tailored forming and targeted design, these magnets can be produced in numerous shapes and sizes, greatly improving design adaptation,
• Important function in new technology industries – they are utilized in data storage devices, rotating machines, clinical machines and sophisticated instruments,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They are fragile when subjected to a heavy impact. If the magnets are exposed to mechanical hits, we recommend in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time strengthens its overall resistance,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent deterioration 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,
• They rust in a humid environment. If exposed to rain, we recommend using sealed magnets, such as those made of polymer,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing fine shapes directly in the magnet,
• Possible threat from tiny pieces may arise, in case of ingestion, which is notable in the context of child safety. Furthermore, tiny components from these products might disrupt scanning once in the system,
• In cases of large-volume purchasing, neodymium magnet cost may not be economically viable,

Maximum holding power of the magnet – what affects it?

The given holding capacity of the magnet represents the highest holding force, assessed in the best circumstances, namely:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with no separation
• with vertical force applied
• in normal thermal conditions

Determinants of lifting force in real conditions

In practice, the holding capacity of a magnet is affected by these factors, 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 measured by applying a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.