SM 32x375 [2xM8] / N42 - magnetic separator

Pros and cons of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have stable power, and over nearly ten years their performance decreases symbolically – ~1% (according to theory),
• Neodymium magnets remain extremely resistant to magnetic field loss caused by external field sources,
• The use of an refined layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Neodymium magnets generate maximum magnetic induction on a small surface, which allows for strong attraction,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to flexibility in constructing and the capacity to modify to complex applications,
• Key role in modern industrial fields – they are utilized in computer drives, motor assemblies, medical equipment, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which allows their use in miniature devices

What to avoid - cons 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 lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in realizing threads and complex forms in magnets, we propose using casing - magnetic mount.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. Furthermore, small elements of these products are able to be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum lifting force for a neodymium magnet – what contributes to it?

The declared magnet strength refers to the peak performance, recorded under optimal environment, meaning:

• on a block made of mild steel, perfectly concentrating the magnetic field
• with a cross-section minimum 10 mm
• with a plane perfectly flat
• under conditions of ideal adhesion (surface-to-surface)
• during detachment in a direction perpendicular to the plane
• at temperature room level

Practical lifting capacity: influencing factors

Real force impacted by specific conditions, including (from priority):

• Air gap (betwixt the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) can cause a drastic drop in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel type – mild steel gives the best results. Alloy steels lower magnetic properties and holding force.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.