SM 25x100 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• They feature excellent resistance to magnetism drop when exposed to external fields,
• By applying a reflective layer of silver, the element presents an elegant look,
• Magnetic induction on the top side of the magnet is extremely intense,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures reaching 230°C and above...
• In view of the option of precise molding and customization to unique needs, magnetic components can be modeled in a wide range of geometric configurations, which makes them more universal,
• Significant place in high-tech industry – they find application in computer drives, motor assemblies, precision medical tools, also technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets decrease their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complex forms in magnets, we recommend using cover - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the aspect of protecting the youngest. Furthermore, small components of these devices can disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity refers to the limit force, measured under optimal environment, namely:

• on a base made of structural steel, effectively closing the magnetic field
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction vertical to the plane
• at ambient temperature approx. 20 degrees Celsius

Magnet lifting force in use – key factors

It is worth knowing that the magnet holding will differ depending on the following factors, in order of importance:

• Distance (betwixt the magnet and the plate), because even a microscopic clearance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Chemical composition of the base – mild steel attracts best. Alloy steels lower magnetic properties and lifting capacity.
• Surface condition – ground elements ensure maximum contact, which increases force. Uneven metal weaken the grip.
• Temperature influence – hot environment reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was measured using a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate reduces the holding force.