SM 25x200 [2xM8] / N52 - magnetic separator

Advantages as well as disadvantages of neodymium magnets.

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

• They have stable power, and over more than 10 years their attraction force decreases symbolically – ~1% (according to theory),
• They do not lose their magnetic properties even under close interference source,
• In other words, due to the reflective surface of gold, the element looks attractive,
• Magnetic induction on the working layer of the magnet remains maximum,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Thanks to versatility in forming and the capacity to adapt to unusual requirements,
• Key role in modern technologies – they are used in magnetic memories, electric motors, medical devices, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in miniature devices

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets decrease 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
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating nuts and complicated forms in magnets, we propose using casing - magnetic mechanism.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Furthermore, tiny parts of these devices are able to complicate diagnosis medical after entering the body.
• Due to neodymium price, their price is higher than average,

Maximum lifting capacity of the magnet – what affects it?

The specified lifting capacity concerns the limit force, recorded under ideal test conditions, specifically:

• on a block made of mild steel, optimally conducting the magnetic flux
• with a thickness minimum 10 mm
• with a plane free of scratches
• with zero gap (without coatings)
• for force applied at a right angle (in the magnet axis)
• at room temperature

Impact of factors on magnetic holding capacity in practice

Bear in mind that the working load will differ depending on elements below, in order of importance:

• Distance (betwixt the magnet and the metal), since even a microscopic distance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to varnish, corrosion or debris).
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds much less (often approx. 20-30% of maximum force).
• Plate thickness – insufficiently thick sheet does not close the flux, causing part of the power to be wasted to the other side.
• Plate material – mild steel gives the best results. Higher carbon content lower magnetic properties and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves field saturation. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity was measured using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.