UMP 75x24 [M8+M10] GW F 200 kg - search holder

Advantages as well as disadvantages of rare earth magnets.

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

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (according to theory),
• Neodymium magnets are distinguished by exceptionally resistant to magnetic field loss caused by external magnetic fields,
• The use of an metallic coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• The surface of neodymium magnets generates a intense magnetic field – this is a distinguishing feature,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures approaching 230°C and above...
• Thanks to the possibility of precise molding and adaptation to custom needs, NdFeB magnets can be created in a broad palette of forms and dimensions, which amplifies use scope,
• Versatile presence in modern industrial fields – they are utilized in magnetic memories, motor assemblies, diagnostic systems, also industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets decrease their force 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 durability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets can be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price exceeds standard values,

Best holding force of the magnet in ideal parameters – what contributes to it?

Information about lifting capacity was defined for the most favorable conditions, including:

• on a base made of mild steel, optimally conducting the magnetic flux
• with a thickness of at least 10 mm
• with a surface cleaned and smooth
• with direct contact (without impurities)
• under vertical force vector (90-degree angle)
• in stable room temperature

Lifting capacity in practice – influencing factors

Bear in mind that the application force may be lower subject to elements below, in order of importance:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Plate material – mild steel attracts best. Alloy admixtures reduce magnetic properties and lifting capacity.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.