SM 25x250 [2xM8] / N52 - magnetic separator

Advantages as well as disadvantages of rare earth magnets.

Besides their exceptional magnetic power, neodymium magnets offer the following advantages:

• They retain attractive force for almost ten years – the loss is just ~1% (according to analyses),
• They do not lose their magnetic properties even under close interference source,
• A magnet with a shiny gold surface is more attractive,
• They are known for high magnetic induction at the operating surface, which improves attraction properties,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• In view of the option of accurate shaping and adaptation to specialized requirements, magnetic components can be modeled in a broad palette of shapes and sizes, which expands the range of possible applications,
• Wide application in electronics industry – they serve a role in magnetic memories, electric motors, diagnostic systems, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which enables their usage in compact constructions

Cons of neodymium magnets: tips and applications.

• At strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• 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 advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing threads in the magnet and complicated shapes - preferred is casing - magnetic holder.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the context of child safety. Additionally, small components of these magnets can complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what it depends on?

The lifting capacity listed is a measurement result performed under specific, ideal conditions:

• on a block made of mild steel, optimally conducting the magnetic flux
• possessing a thickness of minimum 10 mm to avoid saturation
• with an polished contact surface
• with direct contact (no paint)
• during pulling in a direction perpendicular to the mounting surface
• at ambient temperature room level

Practical lifting capacity: influencing factors

In practice, the actual lifting capacity is determined by many variables, ranked from most significant:

• Air gap (between the magnet and the plate), since even a tiny clearance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to paint, rust or debris).
• Force direction – catalog parameter refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Material composition – different alloys reacts the same. High carbon content weaken the interaction with the magnet.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Thermal factor – high temperature reduces magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.