SM 32x250 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of rare earth magnets.

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

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (based on calculations),
• They possess excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• In other words, due to the smooth layer of gold, the element becomes visually attractive,
• Neodymium magnets generate maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of detailed creating and adjusting to precise needs,
• Significant place in modern industrial fields – they are used in HDD drives, electromotive mechanisms, diagnostic systems, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in miniature devices

Problematic aspects of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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 during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating nuts and complex forms in magnets, we recommend using casing - magnetic mechanism.
• Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these devices can disrupt the diagnostic process medical after entering the body.
• Due to expensive raw materials, their price is higher than average,

Detachment force of the magnet in optimal conditions – what affects it?

The force parameter is a theoretical maximum value executed under specific, ideal conditions:

• using a sheet made of mild steel, serving as a ideal flux conductor
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by lack of roughness
• with zero gap (no coatings)
• under perpendicular force vector (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

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

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, 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 reduce magnetic properties and lifting capacity.
• Surface quality – the more even the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal factor – high temperature weakens magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, however under shearing force the load capacity is reduced by as much as 75%. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the holding force.