SMZR 32x125 / N52 - magnetic separator with handle

Pros as well as cons of NdFeB magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• They do not lose their magnetic properties even under strong external field,
• By using a shiny coating of silver, the element has an aesthetic look,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of precise modeling as well as adjusting to concrete applications,
• Versatile presence in electronics industry – they are utilized in computer drives, electric drive systems, advanced medical instruments, as well as multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (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 rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited possibility of producing nuts in the magnet and complex forms - recommended is a housing - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which becomes key in the context of child safety. It is also worth noting that tiny parts of these products are able to complicate diagnosis medical after entering the body.
• With large orders the cost of neodymium magnets can be a barrier,

Maximum lifting force for a neodymium magnet – what contributes to it?

The lifting capacity listed is a theoretical maximum value conducted under standard conditions:

• using a base made of low-carbon steel, functioning as a circuit closing element
• possessing a massiveness of min. 10 mm to avoid saturation
• with an polished contact surface
• without any air gap between the magnet and steel
• during pulling in a direction vertical to the plane
• at conditions approx. 20°C

Impact of factors on magnetic holding capacity in practice

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

• Distance – existence of foreign body (rust, dirt, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Steel type – mild steel gives the best results. Alloy steels lower magnetic permeability and holding force.
• Smoothness – full contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was determined with the use of a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.