SM 18x175 [2xM5] / N42 - magnetic separator

Advantages and disadvantages of rare earth magnets.

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

• They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (according to theory),
• They are noted for resistance to demagnetization induced by external field influence,
• In other words, due to the glossy surface of gold, the element gains visual value,
• Neodymium magnets achieve maximum magnetic induction on a small area, which allows for strong attraction,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Considering the possibility of accurate forming and customization to unique projects, magnetic components can be produced in a wide range of shapes and sizes, which amplifies use scope,
• Key role in innovative solutions – they serve a role in mass storage devices, drive modules, medical equipment, and multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in miniature devices

Disadvantages of NdFeB magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also improves its resistance to damage
• NdFeB magnets lose strength 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 extremely resistant to heat
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We recommend casing - magnetic mount, due to difficulties in creating threads inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child safety. It is also worth noting that tiny parts of these products can be problematic in diagnostics medical after entering the body.
• Due to expensive raw materials, their price is higher than average,

Maximum lifting force for a neodymium magnet – what affects it?

Breakaway force was defined for optimal configuration, taking into account:

• with the application of a sheet made of special test steel, ensuring full magnetic saturation
• whose transverse dimension is min. 10 mm
• characterized by smoothness
• under conditions of ideal adhesion (metal-to-metal)
• under perpendicular force vector (90-degree angle)
• at conditions approx. 20°C

Magnet lifting force in use – key factors

Real force impacted by working environment parameters, including (from priority):

• Distance (between the magnet and the metal), as even a very small distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Load vector – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Steel type – mild steel gives the best results. Alloy admixtures decrease magnetic permeability and holding force.
• Surface finish – full contact is possible only on polished steel. Rough texture create air cushions, weakening the magnet.
• Thermal factor – hot environment weakens magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.