SMZR 25x225 / N52 - magnetic separator with handle

Advantages and disadvantages of neodymium magnets.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They retain magnetic properties for around ten years – the drop is just ~1% (in theory),
• Magnets effectively defend themselves against loss of magnetization caused by ambient magnetic noise,
• A magnet with a smooth gold surface looks better,
• Magnetic induction on the working part of the magnet is extremely intense,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to flexibility in forming and the ability to customize to individual projects,
• Versatile presence in innovative solutions – they are utilized in hard drives, drive modules, advanced medical instruments, also complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Limited possibility of producing threads in the magnet and complicated shapes - recommended is cover - magnetic holder.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which gains importance in the context of child health protection. Additionally, small components of these devices can disrupt the diagnostic process medical after entering the body.
• With mass production the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what affects it?

Breakaway force was defined for optimal configuration, assuming:

• on a block made of structural steel, optimally conducting the magnetic field
• possessing a thickness of min. 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• under perpendicular force direction (90-degree angle)
• at ambient temperature room level

Lifting capacity in practice – influencing factors

Holding efficiency impacted by specific conditions, mainly (from priority):

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note 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.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Plate material – mild steel attracts best. Alloy steels reduce magnetic properties and holding force.
• Surface structure – the more even the plate, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures 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, however under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.