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

Advantages and disadvantages of neodymium magnets.

Apart from their notable holding force, neodymium magnets have these key benefits:

• They retain attractive force for around 10 years – the loss is just ~1% (according to analyses),
• They have excellent resistance to weakening of magnetic properties when exposed to external magnetic sources,
• By covering with a reflective layer of gold, the element gains an modern look,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to flexibility in forming and the capacity to customize to unusual requirements,
• Fundamental importance in electronics industry – they find application in mass storage devices, electric drive systems, diagnostic systems, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which enables their usage in compact constructions

What to avoid - cons of neodymium magnets: weaknesses and usage proposals

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• NdFeB magnets demagnetize 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 very resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We suggest cover - magnetic holder, due to difficulties in producing nuts inside the magnet and complicated forms.
• Potential hazard related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Furthermore, tiny parts of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• Due to complex production process, their price is relatively high,

Maximum lifting force for a neodymium magnet – what contributes to it?

The load parameter shown refers to the maximum value, measured under laboratory conditions, specifically:

• on a block made of structural steel, perfectly concentrating the magnetic field
• possessing a thickness of min. 10 mm to avoid saturation
• with an ideally smooth touching surface
• under conditions of gap-free contact (metal-to-metal)
• under vertical force vector (90-degree angle)
• in temp. approx. 20°C

Lifting capacity in practice – influencing factors

In real-world applications, the real power depends on a number of factors, listed from crucial:

• Distance (between the magnet and the plate), because even a very small distance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Steel thickness – too thin plate does not accept the full field, causing part of the power to be escaped to the other side.
• Material type – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which increases force. Uneven metal reduce efficiency.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, however under parallel forces the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate reduces the holding force.