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 have stable power, and over more than 10 years their performance decreases symbolically – ~1% (according to theory),
• They show high resistance to demagnetization induced by external magnetic fields,
• In other words, due to the shiny layer of silver, the element is aesthetically pleasing,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Due to the possibility of flexible molding and customization to specialized requirements, NdFeB magnets can be modeled in a variety of forms and dimensions, which expands the range of possible applications,
• Universal use in electronics industry – they are utilized in HDD drives, electric drive systems, precision medical tools, and modern systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a special holder, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• We recommend a housing - magnetic mount, due to difficulties in producing threads inside the magnet and complicated shapes.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these magnets can be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what contributes to it?

Magnet power was defined for the most favorable conditions, taking into account:

• on a base made of structural steel, perfectly concentrating the magnetic flux
• with a cross-section no less than 10 mm
• with a plane free of scratches
• without the slightest clearance between the magnet and steel
• under vertical application of breakaway force (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Effective lifting capacity is affected by specific conditions, including (from priority):

• Distance – existence of foreign body (rust, tape, gap) acts as an insulator, which lowers power rapidly (even by 50% at 0.5 mm).
• Load vector – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin sheet does not close the flux, causing part of the power to be wasted to the other side.
• Material type – ideal substrate is high-permeability steel. Hardened steels may attract less.
• Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal reduce efficiency.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, in contrast under parallel forces the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.