MPL 40x18x10 SH / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets.

Besides their exceptional pulling force, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (in laboratory conditions),
• They retain their magnetic properties even under external field action,
• The use of an refined finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• Magnetic induction on the top side of the magnet remains very high,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of accurate creating as well as optimizing to complex conditions,
• Fundamental importance in innovative solutions – they are used in data components, brushless drives, medical equipment, and technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in small systems

Disadvantages of NdFeB magnets:

• At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Due to limitations in producing nuts and complicated shapes in magnets, we recommend using a housing - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these products can disrupt the diagnostic process medical in case of swallowing.
• Due to expensive raw materials, their price is higher than average,

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

The load parameter shown represents the limit force, obtained under optimal environment, namely:

• with the use of a sheet made of low-carbon steel, ensuring maximum field concentration
• possessing a thickness of min. 10 mm to avoid saturation
• with a plane free of scratches
• with zero gap (no paint)
• under axial application of breakaway force (90-degree angle)
• at ambient temperature room level

Lifting capacity in real conditions – factors

Bear in mind that the working load will differ subject to elements below, starting with the most relevant:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds much less (typically approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Steel grade – ideal substrate is pure iron steel. Stainless steels may generate lower lifting capacity.
• Surface finish – ideal contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under shearing force the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet and the plate reduces the holding force.