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

Pros and cons of neodymium magnets.

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

• Their strength remains stable, and after around ten years it decreases only by ~1% (theoretically),
• Magnets effectively defend themselves against loss of magnetization caused by external fields,
• By using a reflective layer of nickel, the element acquires an professional look,
• Magnetic induction on the surface of the magnet is very high,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Considering the ability of flexible forming and adaptation to unique solutions, NdFeB magnets can be created in a variety of forms and dimensions, which amplifies use scope,
• Wide application in modern technologies – they are commonly used in data components, drive modules, precision medical tools, and complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (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 during using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. Furthermore, tiny parts of these devices can complicate diagnosis medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Best holding force of the magnet in ideal parameters – what affects it?

Magnet power was defined for the most favorable conditions, including:

• using a base made of mild steel, serving as a magnetic yoke
• whose transverse dimension equals approx. 10 mm
• with a plane free of scratches
• without the slightest insulating layer between the magnet and steel
• under vertical force direction (90-degree angle)
• at ambient temperature room level

Practical lifting capacity: influencing factors

In practice, the actual lifting capacity results from several key aspects, listed from the most important:

• Gap (between the magnet and the plate), as even a microscopic clearance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – declared lifting capacity refers to detachment 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 restricts the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel attracts best. Alloy steels decrease magnetic properties and holding force.
• Surface quality – the more even the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a small distance {between} the magnet and the plate reduces the holding force.