SM 18x150 [2xM5] / N42 - magnetic separator

Advantages as well as disadvantages of NdFeB magnets.

Apart from their consistent magnetism, neodymium magnets have these key benefits:

• Their magnetic field is maintained, and after approximately 10 years it decreases only by ~1% (according to research),
• They maintain their magnetic properties even under external field action,
• Thanks to the reflective finish, the coating of nickel, gold, or silver gives an aesthetic appearance,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Possibility of custom creating and optimizing to specific conditions,
• Universal use in electronics industry – they serve a role in mass storage devices, electromotive mechanisms, advanced medical instruments, also other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also increases their 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 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited possibility of creating threads in the magnet and complicated shapes - preferred is cover - magnetic holder.
• Health risk to health – tiny shards of magnets are risky, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small components of these products are able to complicate diagnosis medical when they are in the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Breakaway strength of the magnet in ideal conditions – what affects it?

Breakaway force is the result of a measurement for the most favorable conditions, assuming:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ideally smooth contact surface
• under conditions of ideal adhesion (metal-to-metal)
• for force applied at a right angle (in the magnet axis)
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

In practice, the actual lifting capacity is determined by many variables, ranked from the most important:

• Air gap (betwixt the magnet and the metal), as even a very small distance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, rust or debris).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Material composition – not every steel attracts identically. Alloy additives worsen the interaction with the magnet.
• Base smoothness – the more even the plate, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, whereas under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.