SM 32x425 [2xM8] / N52 - magnetic separator

Pros and cons of rare earth magnets.

Besides their remarkable pulling force, neodymium magnets offer the following advantages:

• They have stable power, and over around ten years their performance decreases symbolically – ~1% (according to theory),
• Magnets very well protect themselves against loss of magnetization caused by foreign field sources,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnetic induction on the surface of the magnet turns out to be strong,
• With the right combination of compounds, they reach increased thermal stability, enabling operation at or above 230°C (depending on the form),
• Thanks to freedom in shaping and the capacity to modify to complex applications,
• Universal use in high-tech industry – they find application in computer drives, electric motors, precision medical tools, as well as other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: tips and applications.

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. 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. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• Limited ability of making nuts in the magnet and complex forms - recommended is casing - magnetic holder.
• Possible danger resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. Furthermore, tiny parts of these devices are able to disrupt the diagnostic process medical when they are in the body.
• With mass production the cost of neodymium magnets is economically unviable,

Best holding force of the magnet in ideal parameters – what affects it?

The declared magnet strength refers to the maximum value, recorded under ideal test conditions, meaning:

• using a sheet made of mild steel, serving as a circuit closing element
• with a cross-section no less than 10 mm
• with an ideally smooth contact surface
• with direct contact (no impurities)
• for force acting at a right angle (pull-off, not shear)
• at ambient temperature room level

Practical lifting capacity: influencing factors

In practice, the real power is determined by several key aspects, presented from crucial:

• Space between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Metal type – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
• Smoothness – ideal contact is obtained only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was measured using a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the lifting capacity is smaller. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.