MPL 20x5x5 / N38 - lamellar magnet

Pros and cons of NdFeB magnets.

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

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (based on calculations),
• They maintain their magnetic properties even under external field action,
• By using a reflective layer of nickel, the element presents an proper look,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Due to the potential of flexible shaping and customization to specialized requirements, magnetic components can be produced in a wide range of forms and dimensions, which increases their versatility,
• Key role in advanced technology sectors – they are utilized in magnetic memories, drive modules, medical devices, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in small systems

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves 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 usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Limited ability of creating threads in the magnet and complex shapes - preferred is cover - magnet mounting.
• Health risk to health – tiny shards of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these magnets can disrupt the diagnostic process medical in case of swallowing.
• 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?

The declared magnet strength concerns the maximum value, recorded under optimal environment, specifically:

• on a plate made of mild steel, optimally conducting the magnetic field
• possessing a massiveness of minimum 10 mm to avoid saturation
• with a plane perfectly flat
• without any clearance between the magnet and steel
• during detachment in a direction vertical to the mounting surface
• in neutral thermal conditions

Practical aspects of lifting capacity – factors

In practice, the actual holding force is determined by several key aspects, presented from most significant:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may attract less.
• Surface finish – full contact is possible only on polished steel. Any scratches and bumps create air cushions, weakening the magnet.
• Thermal factor – hot environment weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under shearing force the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.