UMGB 75x28 [M10x3] GW F200 PLATINIUM + Lina GOBLIN / N52 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They retain their full power for around 10 years – the loss is just ~1% (in theory),
• They show strong resistance to demagnetization from outside magnetic sources,
• Thanks to the polished finish and gold coating, they have an elegant appearance,
• They possess intense magnetic force measurable at the magnet’s surface,
• Thanks to their enhanced temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• 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 application range,
• Wide application in modern technologies – they are utilized in data storage devices, electric motors, healthcare devices as well as other advanced devices,
• Thanks to their concentrated strength, small magnets offer high magnetic performance, with minimal size,

Disadvantages of NdFeB magnets:

• They can break when subjected to a strong impact. If the magnets are exposed to physical collisions, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from cracks and strengthens its overall strength,
• They lose power at elevated temperatures. Most neodymium magnets experience permanent decline in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to humidity can rust. Therefore, for outdoor applications, we recommend waterproof types made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing holes directly in the magnet,
• Possible threat linked to microscopic shards may arise, especially if swallowed, which is crucial in the family environments. It should also be noted that miniature parts from these devices have the potential to interfere with diagnostics when ingested,
• High unit cost – neodymium magnets are costlier than other types of magnets (e.g., ferrite), which increases the cost of large-scale applications

Maximum lifting force for a neodymium magnet – what it depends on?

The given pulling force of the magnet represents the maximum force, measured in the best circumstances, namely:

• with mild steel, used as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• with zero air gap
• in a perpendicular direction of force
• in normal thermal conditions

Lifting capacity in practice – influencing factors

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

• 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 measured by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate lowers the holding force.