SM 18x275 [2xM5] / N42 - magnetic separator

Pros and cons of NdFeB magnets.

Besides their immense magnetic power, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (based on calculations),
• They are noted for resistance to demagnetization induced by external disturbances,
• The use of an metallic finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• Magnetic induction on the working layer of the magnet remains maximum,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to the potential of flexible shaping and adaptation to unique solutions, NdFeB magnets can be modeled in a broad palette of forms and dimensions, which amplifies use scope,
• Versatile presence in modern technologies – they are utilized in HDD drives, motor assemblies, precision medical tools, as well as modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a special holder, 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
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complex forms in magnets, we recommend using cover - magnetic mount.
• Potential hazard related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these devices can complicate diagnosis medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Maximum lifting force for a neodymium magnet – what contributes to it?

The specified lifting capacity represents the peak performance, obtained under ideal test conditions, meaning:

• with the application of a yoke made of special test steel, ensuring maximum field concentration
• with a cross-section of at least 10 mm
• characterized by even structure
• without any insulating layer between the magnet and steel
• under axial force vector (90-degree angle)
• at temperature room level

Impact of factors on magnetic holding capacity in practice

During everyday use, the actual holding force is determined by many variables, listed from the most important:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – mild steel attracts best. Alloy steels lower magnetic properties and holding force.
• Surface structure – the more even the plate, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Temperature – temperature increase causes a temporary drop of force. Check the thermal limit for a given model.

* Lifting capacity was measured using a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.