SMZR 32x200 / N52 - magnetic separator with handle

Advantages and disadvantages of neodymium magnets.

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

• They do not lose power, even during around 10 years – the reduction in lifting capacity is only ~1% (based on measurements),
• Magnets perfectly protect themselves against demagnetization caused by external fields,
• In other words, due to the aesthetic finish of nickel, the element is aesthetically pleasing,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• With the right combination of materials, they reach significant thermal stability, enabling operation at or above 230°C (depending on the structure),
• Thanks to freedom in constructing and the capacity to modify to individual projects,
• Universal use in modern industrial fields – they are utilized in hard drives, electric motors, medical devices, also other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

What to avoid - cons of neodymium magnets and ways of using them

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• We suggest cover - magnetic holder, due to difficulties in realizing threads inside the magnet and complicated forms.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Best holding force of the magnet in ideal parameters – what it depends on?

The lifting capacity listed is a theoretical maximum value performed under standard conditions:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• whose transverse dimension equals approx. 10 mm
• with a plane cleaned and smooth
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction vertical to the plane
• in neutral thermal conditions

Lifting capacity in real conditions – factors

During everyday use, the real power results from several key aspects, presented from most significant:

• Distance – the presence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – different alloys attracts identically. High carbon content weaken the attraction effect.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature influence – hot environment reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was assessed by applying a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the lifting capacity is smaller. Additionally, even a small distance {between} the magnet and the plate decreases the holding force.