MW 16x9 / N38 - cylindrical magnet

Advantages and disadvantages of neodymium magnets NdFeB.

Besides their durability, neodymium magnets are valued for these benefits:

• Their strength is durable, and after around ten years, it drops only by ~1% (according to research),
• They are highly resistant to demagnetization caused by external field interference,
• By applying a bright layer of gold, the element gains a clean look,
• They exhibit superior levels of magnetic induction near the outer area of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for accurate shaping or adjustment to individual needs – neodymium magnets can be manufactured in multiple variants of geometries, which amplifies their functionality across industries,
• Significant impact in modern technologies – they serve a purpose in data storage devices, electromechanical systems, diagnostic apparatus as well as high-tech tools,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile when subjected to a strong impact. If the magnets are exposed to shocks, it is advisable to use in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from cracks and additionally increases its overall strength,
• They lose field intensity at extreme temperatures. Most neodymium magnets experience permanent reduction in strength when heated above 80°C (depending on the geometry and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to humidity can corrode. Therefore, for outdoor applications, we recommend waterproof types made of non-metallic composites,
• Using a cover – such as a magnetic holder – is advised due to the limitations in manufacturing threads directly in the magnet,
• Health risk due to small fragments may arise, when consumed by mistake, which is crucial in the context of child safety. Moreover, small elements from these assemblies have the potential to interfere with diagnostics when ingested,
• In cases of large-volume purchasing, neodymium magnet cost may be a barrier,

Maximum magnetic pulling force – what affects it?

The given holding capacity of the magnet corresponds to the highest holding force, determined in the best circumstances, namely:

• with mild steel, used as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• in conditions of no clearance
• in a perpendicular direction of force
• at room temperature

Practical aspects of lifting capacity – factors

Practical lifting force is determined by factors, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, since 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.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, in contrast under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.