MPL 35x7x3 / N38 - lamellar magnet

Advantages as well as disadvantages of NdFeB magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even during nearly ten years – the drop in lifting capacity is only ~1% (theoretically),
• Magnets very well resist against loss of magnetization caused by external fields,
• Thanks to the smooth finish, the surface of Ni-Cu-Ni, gold, or silver-plated gives an modern appearance,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to freedom in forming and the capacity to adapt to client solutions,
• Wide application in future technologies – they serve a role in computer drives, brushless drives, advanced medical instruments, and modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

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.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 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 secure oxidation as well as corrosion.
• Limited ability of creating threads in the magnet and complex forms - recommended is casing - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small components of these devices can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what affects it?

Holding force of 3.71 kg is a result of laboratory testing executed under specific, ideal conditions:

• on a block made of mild steel, perfectly concentrating the magnetic field
• whose transverse dimension is min. 10 mm
• with an ideally smooth touching surface
• with direct contact (no coatings)
• under axial application of breakaway force (90-degree angle)
• at conditions approx. 20°C

Practical aspects of lifting capacity – factors

Holding efficiency is influenced by specific conditions, mainly (from priority):

• Distance (betwixt the magnet and the plate), as even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Load vector – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the surface is typically many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel gives the best results. Higher carbon content lower magnetic properties and holding force.
• Surface quality – the more even the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Thermal environment – temperature increase causes a temporary drop of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, however under shearing force the holding force is lower. In addition, even a slight gap {between} the magnet and the plate reduces the holding force.