UMGB 75x28 [M10x3] GW F200 GOLD +Lina GOBLIN / N42 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (based on calculations),
• They are extremely resistant to demagnetization caused by external field interference,
• Thanks to the glossy finish and silver coating, they have an aesthetic appearance,
• They possess intense magnetic force measurable at the magnet’s surface,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• Thanks to the freedom in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in various configurations, which broadens their application range,
• Important function in advanced technical fields – they find application in HDDs, electric drives, diagnostic apparatus along with sophisticated instruments,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of magnetic elements:

• They are prone to breaking when subjected to a heavy 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 damage and enhances its overall robustness,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent loss 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 humidity can degrade. Therefore, for outdoor applications, we recommend waterproof types made of non-metallic composites,
• Limited ability to create complex details in the magnet – the use of a housing is recommended,
• Health risk due to small fragments may arise, if ingested accidentally, which is crucial in the protection of children. It should also be noted that tiny components from these products might disrupt scanning after being swallowed,
• High unit cost – neodymium magnets are pricier than other types of magnets (e.g., ferrite), which increases the cost of large-scale applications

Maximum lifting force for a neodymium magnet – what affects it?

The given strength of the magnet means the optimal strength, calculated in ideal conditions, specifically:

• with mild steel, serving as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a refined outer layer
• with no separation
• with vertical force applied
• in normal thermal conditions

Impact of factors on magnetic holding capacity in practice

In practice, the holding capacity of a magnet is conditioned by the following aspects, 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 steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a small distance {between} the magnet’s surface and the plate reduces the holding force.