SM 19x225 [2xM6] / N50 - magnetic separator

Pros and cons of NdFeB magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have stable power, and over around 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• Thanks to the elegant finish, the surface of Ni-Cu-Ni, gold-plated, or silver gives an aesthetic appearance,
• Magnets are characterized by very high magnetic induction on the outer side,
• 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...
• Thanks to freedom in shaping and the capacity to modify to individual projects,
• Wide application in electronics industry – they find application in data components, electromotive mechanisms, advanced medical instruments, as well as technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of creating threads in the magnet and complicated shapes - recommended is cover - mounting mechanism.
• Potential hazard related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child health protection. Additionally, tiny parts of these magnets are able to disrupt the diagnostic process medical after entering the body.
• Due to complex production process, their price is higher than average,

Optimal lifting capacity of a neodymium magnet – what it depends on?

Holding force of 0 kg is a theoretical maximum value performed under standard conditions:

• with the use of a yoke made of special test steel, guaranteeing full magnetic saturation
• with a thickness of at least 10 mm
• with a surface free of scratches
• under conditions of no distance (surface-to-surface)
• for force applied at a right angle (pull-off, not shear)
• at standard ambient temperature

Impact of factors on magnetic holding capacity in practice

Real force is influenced by specific conditions, such as (from priority):

• Air gap (betwixt the magnet and the metal), because even a tiny clearance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Chemical composition of the base – low-carbon steel gives the best results. Higher carbon content lower magnetic permeability and lifting capacity.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal environment – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity was measured with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under parallel forces the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet and the plate lowers the lifting capacity.