SM 32x250 [2xM8] / N52 - magnetic separator

Advantages and disadvantages of neodymium magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They retain full power for around ten years – the drop is just ~1% (based on simulations),
• Magnets very well resist against loss of magnetization caused by external fields,
• Thanks to the glossy finish, the surface of nickel, gold, or silver gives an clean appearance,
• Magnetic induction on the surface of the magnet remains impressive,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to freedom in shaping and the ability to adapt to specific needs,
• Fundamental importance in future technologies – they are utilized in computer drives, electric drive systems, advanced medical instruments, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which makes them useful in small systems

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing nuts in the magnet and complicated forms - recommended is cover - magnetic holder.
• Possible danger related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. Additionally, small elements of these magnets can 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 holding power of the magnet – what it depends on?

The specified lifting capacity concerns the limit force, obtained under optimal environment, specifically:

• on a plate made of mild steel, optimally conducting the magnetic flux
• with a cross-section of at least 10 mm
• characterized by even structure
• without any air gap between the magnet and steel
• during pulling in a direction vertical to the plane
• at conditions approx. 20°C

Magnet lifting force in use – key factors

In practice, the actual lifting capacity depends on a number of factors, listed from crucial:

• Distance – existence of any layer (rust, dirt, gap) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds significantly lower power (typically approx. 20-30% of nominal force).
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Metal type – not every steel attracts identically. Alloy additives weaken the interaction with the magnet.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal factor – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was measured using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.