SMZR 32x200 / N52 - magnetic separator with handle

Pros and cons of NdFeB magnets.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They retain attractive force for around ten years – the drop is just ~1% (in theory),
• Magnets very well defend themselves against demagnetization caused by ambient magnetic noise,
• In other words, due to the metallic layer of gold, the element gains visual value,
• Neodymium magnets create maximum magnetic induction on a small surface, which allows for strong attraction,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Due to the option of accurate forming and adaptation to specialized solutions, magnetic components can be manufactured in a wide range of geometric configurations, which increases their versatility,
• Versatile presence in modern technologies – they find application in data components, brushless drives, medical equipment, as well as industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• 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. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in realizing threads and complicated shapes in magnets, we recommend using a housing - magnetic mount.
• Health risk related to microscopic parts of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these products can complicate diagnosis medical after entering the body.
• Due to expensive raw materials, their price exceeds standard values,

Maximum lifting force for a neodymium magnet – what affects it?

The load parameter shown represents the limit force, measured under optimal environment, meaning:

• with the application of a yoke made of special test steel, guaranteeing maximum field concentration
• with a cross-section minimum 10 mm
• characterized by smoothness
• under conditions of no distance (metal-to-metal)
• under perpendicular force direction (90-degree angle)
• at temperature room level

Determinants of lifting force in real conditions

Holding efficiency is influenced by working environment parameters, mainly (from most important):

• Gap (between the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to varnish, rust or dirt).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Base massiveness – insufficiently thick plate does not close the flux, causing part of the flux to be escaped into the air.
• Plate material – low-carbon steel attracts best. Alloy steels lower magnetic permeability and holding force.
• Surface quality – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal environment – temperature increase causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity was determined using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.