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

Advantages as well as disadvantages of neodymium magnets.

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

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They have excellent resistance to magnetism drop when exposed to external fields,
• A magnet with a smooth gold surface has an effective appearance,
• Magnets exhibit huge magnetic induction on the surface,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Due to the option of precise forming and customization to individualized solutions, neodymium magnets can be produced in a wide range of shapes and sizes, which increases their versatility,
• Wide application in modern industrial fields – they serve a role in data components, brushless drives, medical devices, and industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we advise 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 resistant to moisture, in case of application outdoors
• We suggest cover - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Health risk resulting from small fragments of magnets pose a threat, if swallowed, which becomes key in the context of child safety. It is also worth noting that small elements of these products are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what it depends on?

The declared magnet strength concerns the maximum value, recorded under optimal environment, namely:

• with the application of a sheet made of special test steel, ensuring full magnetic saturation
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with a surface perfectly flat
• without the slightest clearance between the magnet and steel
• under vertical force vector (90-degree angle)
• at standard ambient temperature

Practical aspects of lifting capacity – factors

In real-world applications, the actual lifting capacity depends on a number of factors, listed from most significant:

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Load vector – highest force is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin sheet does not accept the full field, causing part of the flux to be escaped into the air.
• Material type – the best choice is high-permeability steel. Stainless steels may attract less.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal factor – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the holding force.