SM 32x275 [2xM8] / N42 - magnetic separator

Pros as well as cons of neodymium magnets.

Besides their tremendous strength, neodymium magnets offer the following advantages:

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (in testing),
• Magnets very well defend themselves against loss of magnetization caused by external fields,
• The use of an elegant coating of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• They show high magnetic induction at the operating surface, which increases their power,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Considering the option of free molding and adaptation to unique projects, NdFeB magnets can be modeled in a broad palette of forms and dimensions, which makes them more universal,
• Huge importance in future technologies – they find application in computer drives, brushless drives, medical equipment, also multitasking production systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

What to avoid - cons of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• NdFeB magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of producing threads in the magnet and complex shapes - recommended is casing - magnet mounting.
• Health risk to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, small components of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
• Due to complex production process, their price is relatively high,

Highest magnetic holding force – what contributes to it?

The specified lifting capacity concerns the limit force, obtained under laboratory conditions, specifically:

• on a plate made of structural steel, optimally conducting the magnetic flux
• whose thickness equals approx. 10 mm
• with a surface cleaned and smooth
• under conditions of ideal adhesion (metal-to-metal)
• during detachment in a direction perpendicular to the plane
• at conditions approx. 20°C

Lifting capacity in practice – influencing factors

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

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Element thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – low-carbon steel gives the best results. Alloy admixtures reduce magnetic properties and lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Uneven metal reduce efficiency.
• Temperature – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under perpendicular forces, in contrast under shearing force the holding force is lower. Additionally, even a small distance {between} the magnet and the plate decreases the load capacity.