SM 32x150 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of neodymium magnets.

Besides their exceptional pulling force, neodymium magnets offer the following advantages:

• They retain magnetic properties for around ten years – the loss is just ~1% (based on simulations),
• Magnets perfectly resist against demagnetization caused by external fields,
• By covering with a smooth layer of silver, the element acquires an professional look,
• They feature high magnetic induction at the operating surface, which affects their effectiveness,
• 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...
• Thanks to versatility in shaping and the capacity to adapt to client solutions,
• Significant place in advanced technology sectors – they serve a role in data components, electromotive mechanisms, precision medical tools, also multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a special holder, which not only protects them against impacts but also raises their durability
• Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of creating threads in the magnet and complicated shapes - preferred is casing - mounting mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child health protection. Furthermore, small elements of these devices can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum holding power of the magnet – what contributes to it?

Breakaway force was defined for ideal contact conditions, assuming:

• on a plate made of structural steel, optimally conducting the magnetic field
• possessing a massiveness of minimum 10 mm to avoid saturation
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction vertical to the plane
• at room temperature

Key elements affecting lifting force

Holding efficiency is influenced by specific conditions, including (from priority):

• Gap between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material type – the best choice is high-permeability steel. Cast iron may have worse magnetic properties.
• Surface structure – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature influence – high temperature weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.