RM R7 SUPER - 13000 Gs / N52 - magnetic distributor

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their tremendous magnetic power, neodymium magnets offer the following advantages:

• They retain their attractive force for almost 10 years – the loss is just ~1% (in theory),
• They show strong resistance to demagnetization from external field exposure,
• Because of the reflective layer of silver, the component looks high-end,
• Magnetic induction on the surface of these magnets is very strong,
• Neodymium magnets are known for exceptionally strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the shape),
• Thanks to the possibility in shaping and the capability to adapt to unique requirements, neodymium magnets can be created in different geometries, which increases their application range,
• Wide application in advanced technical fields – they are used in data storage devices, electromechanical systems, clinical machines or even other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in tiny dimensions, which allows for use in miniature devices

Disadvantages of rare earth magnets:

• They are fragile when subjected to a sudden impact. If the magnets are exposed to external force, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage and additionally enhances its overall robustness,
• They lose field intensity at elevated temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• They rust in a wet environment. If exposed to rain, we recommend using waterproof magnets, such as those made of polymer,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing holes directly in the magnet,
• Possible threat due to small fragments may arise, when consumed by mistake, which is important in the protection of children. Furthermore, small elements from these magnets might hinder health screening once in the system,
• Due to the price of neodymium, their cost is considerably higher,

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

The given pulling force of the magnet means the maximum force, calculated in the best circumstances, specifically:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a smooth surface
• with zero air gap
• with vertical force applied
• under standard ambient temperature

What influences lifting capacity in practice

Practical lifting force is dependent on elements, by priority:

• Air gap between the magnet and the plate, as even a very small distance (e.g. 0.5 mm) can cause a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.