SM 32x250 [2xM8] / N52 - magnetic separator

Advantages as well as disadvantages of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• Their magnetic field remains stable, and after approximately ten years it decreases only by ~1% (theoretically),
• They are extremely resistant to demagnetization induced by external magnetic fields,
• Thanks to the reflective finish, the coating of Ni-Cu-Ni, gold, or silver gives an elegant appearance,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of accurate shaping and modifying to individual conditions,
• Fundamental importance in innovative solutions – they are commonly used in data components, electric drive systems, diagnostic systems, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in small systems

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets start to rust. To use them in conditions 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.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that tiny parts of these magnets can complicate diagnosis medical in case of swallowing.
• Due to expensive raw materials, their price exceeds standard values,

Highest magnetic holding force – what contributes to it?

Holding force of 0 kg is a theoretical maximum value conducted under specific, ideal conditions:

• with the contact of a yoke made of low-carbon steel, ensuring maximum field concentration
• with a thickness minimum 10 mm
• with an ground touching surface
• with direct contact (without paint)
• under axial application of breakaway force (90-degree angle)
• in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

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

• Distance – existence of any layer (rust, dirt, gap) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – mild steel attracts best. Alloy steels reduce magnetic permeability and lifting capacity.
• Surface structure – the more even the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, whereas under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.