MPL 50x20x10 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• Their magnetic field remains stable, and after around 10 years, it drops only by ~1% (theoretically),
• They are highly resistant to demagnetization caused by external magnetic sources,
• By applying a bright layer of silver, the element gains a modern look,
• They exhibit elevated levels of magnetic induction near the outer area of the magnet,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to profile),
• Thanks to the flexibility in shaping and the capability to adapt to unique requirements, neodymium magnets can be created in various configurations, which expands their application range,
• Significant impact in new technology industries – they find application in HDDs, rotating machines, healthcare devices along with high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which makes them ideal in small systems

Disadvantages of magnetic elements:

• They may fracture when subjected to a sudden impact. If the magnets are exposed to external force, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture , and at the same time strengthens its overall durability,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on form). 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 rust. Therefore, for outdoor applications, it's best to use waterproof types made of coated materials,
• Limited ability to create complex details in the magnet – the use of a mechanical support is recommended,
• Possible threat from tiny pieces may arise, if ingested accidentally, which is notable in the protection of children. Furthermore, minuscule fragments from these devices can hinder health screening when ingested,
• High unit cost – neodymium magnets are pricier than other types of magnets (e.g., ferrite), which can restrict large-scale applications

Maximum lifting capacity of the magnet – what contributes to it?

The given lifting capacity of the magnet means the maximum lifting force, assessed in ideal conditions, that is:

• with mild steel, used as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• with zero air gap
• in a perpendicular direction of force
• under standard ambient temperature

Determinants of lifting force in real conditions

The lifting capacity of a magnet is influenced by in practice the following factors, according to their importance:

• 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 assessed using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate reduces the load capacity.