SM 32x125 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of neodymium magnets.

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

• They virtually do not lose power, because even after 10 years the performance loss is only ~1% (according to literature),
• They retain their magnetic properties even under close interference source,
• Thanks to the glossy finish, the plating of Ni-Cu-Ni, gold-plated, or silver gives an aesthetic appearance,
• Magnets exhibit extremely high magnetic induction on the active area,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Possibility of accurate shaping and modifying to atypical conditions,
• Versatile presence in high-tech industry – they serve a role in computer drives, drive modules, medical equipment, as well as modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which enables their usage in small systems

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing 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 strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of creating nuts in the magnet and complex forms - recommended is cover - magnetic holder.
• Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity represents the limit force, recorded under optimal environment, meaning:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• whose transverse dimension equals approx. 10 mm
• characterized by smoothness
• with total lack of distance (no paint)
• during detachment in a direction vertical to the mounting surface
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

During everyday use, the actual lifting capacity is determined by many variables, ranked from the most important:

• Distance – the presence of foreign body (rust, dirt, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Metal type – different alloys attracts identically. High carbon content worsen the attraction effect.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal environment – heating the magnet results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* 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 small distance {between} the magnet and the plate decreases the load capacity.