ZM XMAG2 105 elementów - magnetic toy

Advantages as well as disadvantages of neodymium magnets.

Besides their exceptional magnetic power, neodymium magnets offer the following advantages:

• They have stable power, and over nearly 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They are noted for resistance to demagnetization induced by presence of other magnetic fields,
• In other words, due to the aesthetic surface of silver, the element gains visual value,
• Magnetic induction on the top side of the magnet is maximum,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to versatility in forming and the capacity to adapt to client solutions,
• Key role in electronics industry – they are utilized in mass storage devices, electric drive systems, medical equipment, and complex engineering applications.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets and proposals for their use:

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves 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.
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads 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 is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these devices can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what it depends on?

Information about lifting capacity was defined for ideal contact conditions, taking into account:

• with the contact of a sheet made of low-carbon steel, ensuring full magnetic saturation
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an ideally smooth touching surface
• with zero gap (without coatings)
• for force applied at a right angle (pull-off, not shear)
• at temperature room level

Magnet lifting force in use – key factors

Effective lifting capacity is affected by working environment parameters, mainly (from priority):

• Gap between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to detachment vertically. When slipping, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – mild steel attracts best. Alloy admixtures lower magnetic properties and holding force.
• Surface condition – smooth surfaces ensure maximum contact, which improves force. Uneven metal weaken the grip.
• Heat – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was measured with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, however under parallel forces the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.