SMZR 25x175 / N52 - magnetic separator with handle

Pros and cons of rare earth magnets.

Besides their tremendous magnetic power, neodymium magnets offer the following advantages:

• Their power is maintained, and after approximately 10 years it decreases only by ~1% (according to research),
• They retain their magnetic properties even under close interference source,
• The use of an elegant layer of noble metals (nickel, gold, silver) causes the element to present itself better,
• Magnets exhibit huge magnetic induction on the outer side,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Considering the ability of free molding and customization to specialized projects, neodymium magnets can be produced in a variety of shapes and sizes, which increases their versatility,
• Significant place in modern industrial fields – they find application in hard drives, brushless drives, medical devices, as well as other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we suggest using special steel housings. 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 weakening of strength (a factor is the shape as well as 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 when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of making threads in the magnet and complex shapes - recommended is a housing - mounting mechanism.
• Potential hazard to health – tiny shards of magnets are risky, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small components of these magnets can be problematic in diagnostics medical after entering the body.
• With budget limitations the cost of neodymium magnets is a challenge,

Maximum holding power of the magnet – what it depends on?

The force parameter is a result of laboratory testing executed under the following configuration:

• using a plate made of low-carbon steel, serving as a ideal flux conductor
• possessing a thickness of at least 10 mm to avoid saturation
• with a surface perfectly flat
• under conditions of ideal adhesion (surface-to-surface)
• during pulling in a direction vertical to the plane
• at temperature room level

Practical aspects of lifting capacity – factors

Please note that the application force will differ subject to elements below, starting with the most relevant:

• Distance (betwixt the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of nominal force).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel attracts identically. Alloy additives worsen the interaction with the magnet.
• Surface quality – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, however under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.