SM 25x225 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

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

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (based on calculations),
• They are noted for resistance to demagnetization induced by external disturbances,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to versatility in constructing and the capacity to customize to specific needs,
• Key role in advanced technology sectors – they serve a role in data components, electric motors, medical equipment, as well as other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Problematic aspects of neodymium magnets and ways of using them

• At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of creating nuts in the magnet and complex shapes - preferred is casing - magnetic holder.
• Possible danger to health – tiny shards of magnets can be dangerous, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these products can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what affects it?

The load parameter shown refers to the maximum value, recorded under ideal test conditions, namely:

• on a block made of structural steel, perfectly concentrating the magnetic field
• possessing a thickness of at least 10 mm to ensure full flux closure
• characterized by lack of roughness
• without the slightest air gap between the magnet and steel
• during detachment in a direction vertical to the mounting surface
• in stable room temperature

Magnet lifting force in use – key factors

Please note that the working load may be lower depending on elements below, starting with the most relevant:

• Distance – the presence of any layer (paint, dirt, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Material type – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Smoothness – ideal contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – temperature increase results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate lowers the load capacity.