SM 32x225 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

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

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• Magnets effectively protect themselves against demagnetization caused by foreign field sources,
• In other words, due to the aesthetic layer of silver, the element gains a professional look,
• Neodymium magnets generate maximum magnetic induction on a contact point, which ensures high operational 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...
• In view of the ability of precise forming and customization to unique projects, NdFeB magnets can be created in a wide range of forms and dimensions, which makes them more universal,
• Huge importance in future technologies – they serve a role in mass storage devices, electromotive mechanisms, diagnostic systems, also multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a special holder, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited ability of producing threads in the magnet and complex shapes - preferred is casing - magnetic holder.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these magnets can complicate diagnosis medical after entering the body.
• With mass production the cost of neodymium magnets can be a barrier,

Optimal lifting capacity of a neodymium magnet – what it depends on?

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

• with the use of a sheet made of special test steel, ensuring full magnetic saturation
• whose transverse dimension equals approx. 10 mm
• with a plane free of scratches
• without any air gap between the magnet and steel
• under axial force direction (90-degree angle)
• in neutral thermal conditions

Key elements affecting lifting force

During everyday use, the actual lifting capacity is determined by many variables, presented from the most important:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Plate thickness – too thin sheet does not close the flux, causing part of the power to be lost into the air.
• Steel type – low-carbon steel attracts best. Higher carbon content lower magnetic permeability and holding force.
• Surface finish – full contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – heating the magnet causes a temporary drop of force. Check the thermal limit for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate lowers the holding force.