ZM XMAG2 105 elementów - magnetic toy

Pros as well as cons of neodymium magnets.

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

• They have constant strength, and over more than ten years their attraction force decreases symbolically – ~1% (according to theory),
• They possess excellent resistance to magnetism drop due to external magnetic sources,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of individual creating as well as optimizing to specific needs,
• Fundamental importance in modern technologies – they are commonly used in mass storage devices, electric motors, medical devices, and multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• 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 advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in producing threads and complicated shapes in magnets, we propose using a housing - magnetic mount.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which is particularly important in the context of child safety. Additionally, tiny parts of these devices can complicate diagnosis medical when they are in 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 affects it?

The force parameter is a theoretical maximum value performed under specific, ideal conditions:

• with the use of a sheet made of low-carbon steel, ensuring full magnetic saturation
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with a surface cleaned and smooth
• with total lack of distance (no coatings)
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

What influences lifting capacity in practice

Effective lifting capacity is influenced by specific conditions, such as (from most important):

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin sheet does not close the flux, causing part of the power to be escaped into the air.
• Steel grade – the best choice is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Surface finish – ideal contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Temperature influence – high temperature reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.