SMZR 32x125 / N52 - magnetic separator with handle

Strengths as well as weaknesses of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• Their strength is durable, and after around 10 years it decreases only by ~1% (according to research),
• They have excellent resistance to magnetic field loss due to opposing magnetic fields,
• By applying a lustrous coating of gold, the element acquires an elegant look,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the potential of accurate molding and adaptation to specialized requirements, neodymium magnets can be created in a variety of forms and dimensions, which makes them more universal,
• Wide application in advanced technology sectors – they are used in magnetic memories, electromotive mechanisms, precision medical tools, as well as multitasking production systems.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Cons of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening 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
• 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 prevent oxidation and corrosion.
• We suggest casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated shapes.
• Health risk to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products can disrupt the diagnostic process medical after entering the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

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

The specified lifting capacity represents the peak performance, recorded under optimal environment, namely:

• using a plate made of low-carbon steel, serving as a circuit closing element
• whose thickness is min. 10 mm
• characterized by smoothness
• under conditions of no distance (metal-to-metal)
• under perpendicular force vector (90-degree angle)
• in neutral thermal conditions

What influences lifting capacity in practice

Effective lifting capacity impacted by specific conditions, including (from most important):

• Distance (betwixt the magnet and the plate), because even a tiny distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Steel grade – the best choice is pure iron steel. Hardened steels may have worse magnetic properties.
• Base smoothness – the more even the plate, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Operating temperature – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under shearing force the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the holding force.