SM 18x300 [2xM5] / N42 - magnetic separator

Advantages as well as disadvantages of NdFeB magnets.

Apart from their superior power, neodymium magnets have these key benefits:

• They do not lose magnetism, even during approximately 10 years – the reduction in power is only ~1% (according to tests),
• Magnets very well protect themselves against demagnetization caused by external fields,
• A magnet with a smooth gold surface looks better,
• They feature high magnetic induction at the operating surface, which affects their effectiveness,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of individual shaping as well as modifying to specific requirements,
• Universal use in high-tech industry – they find application in mass storage devices, motor assemblies, diagnostic systems, and modern systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium 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 extremely resistant to heat
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated shapes in magnets, we propose using casing - magnetic mount.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these devices can disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what it depends on?

The declared magnet strength refers to the maximum value, recorded under ideal test conditions, namely:

• on a base made of mild steel, effectively closing the magnetic flux
• with a thickness minimum 10 mm
• with a plane free of scratches
• under conditions of gap-free contact (surface-to-surface)
• under perpendicular force vector (90-degree angle)
• at room temperature

Lifting capacity in practice – influencing factors

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

• Gap (between the magnet and the metal), since even a very small distance (e.g. 0.5 mm) results in a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Angle of force application – maximum parameter is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is typically several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel causes magnetic saturation, causing part of the flux to be wasted to the other side.
• Material type – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Uneven metal reduce efficiency.
• Temperature – heating the magnet causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under shearing force the load capacity is reduced by as much as 75%. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.