SM 32x375 [2xM8] / N42 - magnetic separator

Pros as well as cons of neodymium magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They do not lose strength, even during nearly ten years – the reduction in lifting capacity is only ~1% (theoretically),
• They maintain their magnetic properties even under external field action,
• By applying a shiny coating of gold, the element presents an aesthetic look,
• Magnetic induction on the working part of the magnet is very high,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of exact creating as well as adapting to precise requirements,
• Universal use in future technologies – they find application in computer drives, electric drive systems, precision medical tools, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which makes them useful in compact constructions

Disadvantages of NdFeB magnets:

• 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 power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We suggest cover - magnetic mount, due to difficulties in creating nuts inside the magnet and complex shapes.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which gains importance in the context of child health protection. Furthermore, tiny parts of these magnets can disrupt the diagnostic process medical when they are in the body.
• Due to expensive raw materials, their price is higher than average,

Highest magnetic holding force – what contributes to it?

Holding force of 0 kg is a measurement result executed under the following configuration:

• on a plate made of mild steel, effectively closing the magnetic field
• possessing a massiveness of at least 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of ideal adhesion (surface-to-surface)
• under vertical application of breakaway force (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

Bear in mind that the working load will differ subject to elements below, starting with the most relevant:

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Direction of force – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface 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 passes through the material instead of converting into lifting capacity.
• Material composition – not every steel attracts identically. Alloy additives weaken the attraction effect.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the holding force.