MPL 60x10x5 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after ten years, the decline in efficiency is only ~1% (in laboratory conditions),
• They remain magnetized despite exposure to magnetic noise,
• Thanks to the glossy finish and nickel coating, they have an aesthetic appearance,
• They possess significant magnetic force measurable at the magnet’s surface,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Thanks to the flexibility in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in diverse shapes and sizes, which increases their usage potential,
• Significant impact in cutting-edge sectors – they are used in HDDs, electric drives, medical equipment and sophisticated instruments,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in tiny dimensions, which allows for use in compact constructions

Disadvantages of magnetic elements:

• They can break when subjected to a strong impact. If the magnets are exposed to mechanical hits, we recommend in a protective case. The steel housing, in the form of a holder, protects the magnet from breakage and additionally reinforces its overall robustness,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible power drop (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to damp air can rust. Therefore, for outdoor applications, we suggest waterproof types made of coated materials,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing complex structures directly in the magnet,
• Possible threat related to magnet particles may arise, when consumed by mistake, which is notable in the family environments. Additionally, small elements from these products can complicate medical imaging when ingested,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which may limit large-scale applications

Maximum magnetic pulling force – what contributes to it?

The given lifting capacity of the magnet represents the maximum lifting force, measured in the best circumstances, specifically:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a polished side
• with zero air gap
• under perpendicular detachment force
• at room temperature

Determinants of practical lifting force of a magnet

Practical lifting force is dependent on elements, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, since 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.

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.