SM 32x375 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

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

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets are distinguished by extremely resistant to demagnetization caused by external interference,
• A magnet with a shiny silver surface looks better,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to modularity in forming and the capacity to adapt to client solutions,
• Fundamental importance in modern industrial fields – they find application in mass storage devices, brushless drives, diagnostic systems, as well as technologically advanced constructions.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

What to avoid - cons of neodymium magnets and ways of using them

• At very strong impacts they can crack, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• Limited ability of producing nuts in the magnet and complex forms - preferred is a housing - mounting mechanism.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. It is also worth noting that tiny parts of these products are able to be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

Information about lifting capacity was determined for the most favorable conditions, taking into account:

• on a base made of structural steel, optimally conducting the magnetic flux
• possessing a thickness of at least 10 mm to avoid saturation
• with an ground contact surface
• under conditions of ideal adhesion (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• at conditions approx. 20°C

Magnet lifting force in use – key factors

Effective lifting capacity impacted by working environment parameters, mainly (from priority):

• Clearance – the presence of foreign body (paint, tape, gap) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Metal type – different alloys attracts identically. High carbon content weaken the attraction effect.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Temperature influence – high temperature weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed with the use of a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a minimal clearance {between} the magnet and the plate decreases the holding force.