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

Advantages as well as disadvantages of NdFeB magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even during around ten years – the decrease in strength is only ~1% (based on measurements),
• They feature excellent resistance to magnetic field loss due to opposing magnetic fields,
• Thanks to the elegant finish, the layer of nickel, gold, or silver-plated gives an professional appearance,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which increases force concentration,
• 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 ability of accurate forming and customization to unique projects, NdFeB magnets can be created in a broad palette of shapes and sizes, which makes them more universal,
• Significant place in future technologies – they are commonly used in magnetic memories, electric drive systems, advanced medical instruments, and complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Cons of neodymium magnets: application proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We suggest cover - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Potential hazard resulting from small fragments of magnets are risky, when accidentally swallowed, which becomes key in the context of child safety. Additionally, tiny parts of these magnets are able to complicate diagnosis medical after entering the body.
• With mass production the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what affects it?

Information about lifting capacity was defined for ideal contact conditions, assuming:

• with the use of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of minimum 10 mm to avoid saturation
• with a surface cleaned and smooth
• without the slightest air gap between the magnet and steel
• under vertical force direction (90-degree angle)
• in neutral thermal conditions

Determinants of lifting force in real conditions

In practice, the actual lifting capacity is determined by a number of factors, listed from most significant:

• Gap (betwixt the magnet and the plate), because even a tiny clearance (e.g. 0.5 mm) can cause a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Material composition – not every steel attracts identically. Alloy additives weaken the attraction effect.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Heat – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under parallel forces the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate decreases the load capacity.