MPL 40x18x10 SH / N38 - lamellar magnet

Pros and cons of rare earth magnets.

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

• They have unchanged lifting capacity, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• They have excellent resistance to weakening of magnetic properties when exposed to opposing magnetic fields,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• They show high magnetic induction at the operating surface, making them more effective,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to flexibility in designing and the capacity to customize to complex applications,
• Fundamental importance in modern technologies – they are utilized in magnetic memories, electromotive mechanisms, medical equipment, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which enables their usage in small systems

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• NdFeB magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• They oxidize in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child health protection. Additionally, tiny parts of these magnets can complicate diagnosis medical when they are in the body.
• Due to expensive raw materials, their price is higher than average,

Maximum lifting capacity of the magnet – what it depends on?

Holding force of 0 kg is a result of laboratory testing conducted under the following configuration:

• with the use of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• with a thickness minimum 10 mm
• with a surface cleaned and smooth
• with total lack of distance (no impurities)
• during detachment in a direction vertical to the mounting surface
• at standard ambient temperature

Practical lifting capacity: influencing factors

Bear in mind that the application force may be lower influenced by the following factors, in order of importance:

• Gap (betwixt the magnet and the plate), as even a tiny clearance (e.g. 0.5 mm) leads to a reduction in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Load vector – highest force is obtained only during pulling at a 90° angle. The shear force of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Steel type – mild steel gives the best results. Higher carbon content lower magnetic permeability and lifting capacity.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal environment – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.