SM 25x125 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of NdFeB magnets.

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

• They retain full power for almost ten years – the drop is just ~1% (according to analyses),
• They are extremely resistant to demagnetization induced by external field influence,
• The use of an elegant finish of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• In view of the potential of accurate molding and adaptation to unique projects, neodymium magnets can be created in a wide range of forms and dimensions, which makes them more universal,
• Key role in electronics industry – they are commonly used in hard drives, electric motors, medical devices, as well as complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited possibility of producing nuts in the magnet and complicated shapes - recommended is cover - mounting mechanism.
• Possible danger related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these products are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Breakaway strength of the magnet in ideal conditions – what it depends on?

The load parameter shown concerns the maximum value, obtained under optimal environment, namely:

• on a block made of structural steel, optimally conducting the magnetic field
• whose transverse dimension reaches at least 10 mm
• with a plane cleaned and smooth
• with total lack of distance (without paint)
• under axial force vector (90-degree angle)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

In real-world applications, the actual holding force is determined by a number of factors, presented from the most important:

• Distance – existence of any layer (paint, dirt, gap) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material composition – not every steel reacts the same. Alloy additives weaken the attraction effect.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Thermal factor – high temperature reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.