SM 18x300 [2xM5] / N42 - magnetic separator

Pros and cons of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They retain attractive force for nearly ten years – the loss is just ~1% (in theory),
• Neodymium magnets are remarkably resistant to loss of magnetic properties caused by external field sources,
• In other words, due to the reflective layer of silver, the element gains visual value,
• Magnetic induction on the surface of the magnet is very high,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of detailed forming as well as modifying to complex conditions,
• Wide application in electronics industry – they find application in data components, electromotive mechanisms, precision medical tools, and industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a strong case, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest 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 and corrosion.
• Limited possibility of making nuts in the magnet and complex forms - recommended is casing - magnet mounting.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. Additionally, small components of these products can complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets can be a barrier,

Detachment force of the magnet in optimal conditions – what it depends on?

Magnet power was determined for ideal contact conditions, including:

• with the application of a yoke made of low-carbon steel, ensuring maximum field concentration
• whose thickness reaches at least 10 mm
• with an ideally smooth contact surface
• under conditions of gap-free contact (metal-to-metal)
• under axial force vector (90-degree angle)
• at standard ambient temperature

Lifting capacity in real conditions – factors

Effective lifting capacity is affected by working environment parameters, such as (from priority):

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (often approx. 20-30% of nominal force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Plate material – mild steel attracts best. Alloy admixtures lower magnetic permeability and holding force.
• Surface structure – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was assessed using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the holding force.