ZM XMAG2 210 elementów - magnetic toy

Advantages as well as disadvantages of NdFeB magnets.

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

• They have stable power, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• Neodymium magnets prove to be exceptionally resistant to loss of magnetic properties caused by external field sources,
• In other words, due to the aesthetic surface of gold, the element becomes visually attractive,
• They feature high magnetic induction at the operating surface, which affects their effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Possibility of precise modeling and adapting to individual needs,
• Versatile presence in innovative solutions – they are used in HDD drives, electric drive systems, medical devices, also other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (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
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complicated forms in magnets, we propose using casing - magnetic mechanism.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, small elements of these magnets can disrupt the diagnostic process 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 affects it?

The declared magnet strength represents the peak performance, recorded under optimal environment, meaning:

• using a sheet made of low-carbon steel, acting as a circuit closing element
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ground touching surface
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (pull-off, not shear)
• in stable room temperature

Determinants of lifting force in real conditions

Real force impacted by specific conditions, such as (from most important):

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – maximum parameter is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel does not accept the full field, causing part of the flux to be lost into the air.
• Material composition – not every steel reacts the same. Alloy additives weaken the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.