SMZR 32x150 / N52 - magnetic separator with handle

Pros and cons of neodymium magnets.

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

• Their power remains stable, and after approximately 10 years it drops only by ~1% (according to research),
• Neodymium magnets prove to be remarkably resistant to magnetic field loss caused by external field sources,
• The use of an refined finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of detailed machining as well as modifying to individual conditions,
• Wide application in future technologies – they serve a role in HDD drives, brushless drives, diagnostic systems, and multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Cons of neodymium magnets and ways of using them

• At very strong impacts they can crack, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets decrease their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. 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 corrode. Therefore when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in realizing nuts and complicated shapes in magnets, we propose using a housing - magnetic mechanism.
• Possible danger resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that small components of these devices can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

Breakaway force was defined for ideal contact conditions, including:

• with the contact of a yoke made of low-carbon steel, ensuring maximum field concentration
• possessing a massiveness of at least 10 mm to avoid saturation
• characterized by lack of roughness
• with total lack of distance (no paint)
• under perpendicular force vector (90-degree angle)
• in stable room temperature

Magnet lifting force in use – key factors

Holding efficiency is influenced by specific conditions, mainly (from most important):

• Clearance – the presence of any layer (rust, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Plate material – low-carbon steel gives the best results. Alloy steels decrease magnetic properties and holding force.
• Surface quality – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, however under shearing force the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet and the plate lowers the load capacity.