ZM XMAG2 105 elementów - magnetic toy

Pros and cons of neodymium magnets.

Apart from their notable power, neodymium magnets have these key benefits:

• They do not lose magnetism, even after around ten years – the drop in strength is only ~1% (based on measurements),
• They show high resistance to demagnetization induced by external disturbances,
• In other words, due to the metallic layer of gold, the element gains visual value,
• Neodymium magnets achieve maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• 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...
• Possibility of accurate creating and optimizing to complex needs,
• Fundamental importance in modern technologies – they are utilized in HDD drives, electric drive systems, advanced medical instruments, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in small systems

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We recommend a housing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that small elements of these devices can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what it depends on?

The specified lifting capacity concerns the limit force, recorded under optimal environment, meaning:

• on a base made of structural steel, effectively closing the magnetic flux
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with a plane free of scratches
• under conditions of no distance (surface-to-surface)
• under axial application of breakaway force (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Bear in mind that the working load may be lower depending on elements below, starting with the most relevant:

• Air gap (between the magnet and the plate), because even a microscopic clearance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet holds much less (typically approx. 20-30% of nominal force).
• Steel thickness – too thin steel causes magnetic saturation, causing part of the flux to be escaped to the other side.
• Metal type – different alloys reacts the same. High carbon content weaken the interaction with the magnet.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Thermal factor – high temperature weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was determined by applying a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate lowers the holding force.