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

Pros and cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• Their strength remains stable, and after approximately ten years it decreases only by ~1% (theoretically),
• Neodymium magnets are extremely resistant to demagnetization caused by magnetic disturbances,
• In other words, due to the metallic finish of silver, the element gains a professional look,
• Neodymium magnets deliver maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to the ability of precise forming and adaptation to specialized requirements, neodymium magnets can be modeled in a variety of forms and dimensions, which increases their versatility,
• Versatile presence in modern technologies – they serve a role in computer drives, electromotive mechanisms, precision medical tools, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which allows their use in small systems

Disadvantages of NdFeB magnets:

• At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic holder, due to difficulties in realizing threads inside the magnet and complex shapes.
• Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these products are able to disrupt the diagnostic process medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Optimal lifting capacity of a neodymium magnet – what affects it?

The specified lifting capacity represents the maximum value, measured under ideal test conditions, namely:

• with the contact of a yoke made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension equals approx. 10 mm
• characterized by even structure
• with zero gap (no paint)
• during pulling in a direction perpendicular to the mounting surface
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

Effective lifting capacity is affected by working environment parameters, including (from most important):

• Distance – the presence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – mild steel gives the best results. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Surface structure – the more even the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.