ZM XMAG2 105 elementów - magnetic toy

Pros as well as cons of neodymium magnets.

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

• They retain full power for almost 10 years – the drop is just ~1% (based on simulations),
• Neodymium magnets are distinguished by remarkably resistant to magnetic field loss caused by magnetic disturbances,
• By covering with a smooth coating of gold, the element has an elegant look,
• The surface of neodymium magnets generates a intense magnetic field – this is a distinguishing feature,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures reaching 230°C and above...
• Thanks to freedom in constructing and the ability to modify to specific needs,
• Wide application in modern technologies – they are used in HDD drives, electric drive systems, diagnostic systems, also other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets lose their strength 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 stability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• We recommend cover - magnetic mechanism, due to difficulties in producing nuts inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• With large orders the cost of neodymium magnets can be a barrier,

Magnetic strength at its maximum – what affects it?

The specified lifting capacity represents the maximum value, measured under optimal environment, meaning:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of min. 10 mm to ensure full flux closure
• with a surface perfectly flat
• with total lack of distance (without paint)
• under axial application of breakaway force (90-degree angle)
• at standard ambient temperature

Lifting capacity in real conditions – factors

In real-world applications, the actual lifting capacity depends on several key aspects, presented from most significant:

• Gap (betwixt the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Material type – the best choice is high-permeability steel. Hardened steels may attract less.
• Surface quality – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was determined using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.