MPL 30x10x8 / N38 - lamellar magnet

Advantages and disadvantages of rare earth magnets.

Apart from their strong holding force, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (based on calculations),
• They do not lose their magnetic properties even under close interference source,
• Thanks to the smooth finish, the plating of Ni-Cu-Ni, gold, or silver gives an professional appearance,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Considering the option of accurate forming and adaptation to specialized solutions, magnetic components can be modeled in a broad palette of geometric configurations, which expands the range of possible applications,
• Fundamental importance in modern industrial fields – they serve a role in mass storage devices, electric drive systems, precision medical tools, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in small systems

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and 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
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited ability of producing nuts in the magnet and complicated forms - preferred is casing - magnet mounting.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child health protection. It is also worth noting that small elements of these magnets are able to complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what affects it?

The force parameter is a measurement result executed under the following configuration:

• on a plate made of structural steel, optimally conducting the magnetic flux
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ground contact surface
• with zero gap (without coatings)
• under axial force direction (90-degree angle)
• at conditions approx. 20°C

Lifting capacity in practice – influencing factors

Bear in mind that the working load may be lower depending on the following factors, starting with the most relevant:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Load vector – maximum parameter is available only during perpendicular pulling. The resistance to sliding of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of converting into lifting capacity.
• Material type – ideal substrate is pure iron steel. Stainless steels may have worse magnetic properties.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves field saturation. Uneven metal reduce efficiency.
• Heat – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, whereas under shearing force the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate reduces the holding force.