MPL 40x10x4 / N38 - lamellar magnet

Strengths as well as weaknesses of rare earth magnets.

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

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (according to literature),
• They are extremely resistant to demagnetization induced by external disturbances,
• Thanks to the elegant finish, the surface of Ni-Cu-Ni, gold, or silver-plated gives an clean appearance,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which increases force concentration,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• Possibility of individual machining and adjusting to complex conditions,
• Versatile presence in high-tech industry – they are commonly used in data components, drive modules, medical devices, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in miniature devices

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• NdFeB magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (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 extremely resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing nuts and complicated shapes in magnets, we recommend using casing - magnetic mount.
• Health risk to health – tiny shards of magnets pose a threat, if swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small components of these magnets can complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what it depends on?

The load parameter shown concerns the peak performance, obtained under laboratory conditions, namely:

• using a base made of mild steel, functioning as a circuit closing element
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

In practice, the real power is determined by many variables, presented from most significant:

• Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel reacts the same. High carbon content weaken the interaction with the magnet.
• Base smoothness – the more even the plate, the larger the contact zone and stronger the hold. Unevenness acts like micro-gaps.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity was determined by applying a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under parallel forces the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.