SM 18x275 [2xM5] / N42 - magnetic separator

Strengths and weaknesses of neodymium magnets.

Apart from their notable magnetism, neodymium magnets have these key benefits:

• Their magnetic field remains stable, and after approximately 10 years it drops only by ~1% (according to research),
• They possess excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• In other words, due to the shiny surface of gold, the element looks attractive,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• In view of the potential of precise shaping and customization to specialized solutions, magnetic components can be modeled in a broad palette of forms and dimensions, which increases their versatility,
• Significant place in modern industrial fields – they find application in data components, electromotive mechanisms, advanced medical instruments, also other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited ability of making nuts in the magnet and complex shapes - preferred is cover - mounting mechanism.
• Health risk resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small components of these magnets are able to be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

The load parameter shown represents the maximum value, recorded under laboratory conditions, specifically:

• on a base made of structural steel, perfectly concentrating the magnetic field
• whose thickness equals approx. 10 mm
• characterized by even structure
• with total lack of distance (no impurities)
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

What influences lifting capacity in practice

Bear in mind that the working load will differ subject to the following factors, starting with the most relevant:

• Distance (betwixt the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) can cause a drastic drop in force by up to 50% (this also applies to paint, corrosion or debris).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds much less (often approx. 20-30% of maximum force).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of generating force.
• Plate material – mild steel attracts best. Alloy admixtures reduce magnetic permeability and holding force.
• Surface finish – full contact is possible only on polished steel. Rough texture create air cushions, reducing force.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured by applying a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.