UMP 75x25 [M10x3] GW F200 GOLD / N42 - search holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from their superior magnetic energy, neodymium magnets have these key benefits:

• They have unchanged lifting capacity, and over more than 10 years their performance decreases symbolically – ~1% (in testing),
• They protect against demagnetization induced by ambient electromagnetic environments effectively,
• By applying a shiny layer of silver, the element gains a sleek look,
• The outer field strength of the magnet shows elevated magnetic properties,
• Thanks to their enhanced temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• The ability for precise shaping and adaptation to individual needs – neodymium magnets can be manufactured in multiple variants of geometries, which extends the scope of their use cases,
• Key role in cutting-edge sectors – they find application in data storage devices, electric drives, clinical machines or even other advanced devices,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They can break when subjected to a sudden 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 breakage and reinforces its overall durability,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is advisable to use sealed magnets made of plastic for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing fine shapes directly in the magnet,
• Potential hazard from tiny pieces may arise, in case of ingestion, which is significant in the protection of children. It should also be noted that miniature parts from these devices have the potential to hinder health screening if inside the body,
• In cases of tight budgets, neodymium magnet cost may not be economically viable,

Optimal lifting capacity of a neodymium magnet – what affects it?

The given lifting capacity of the magnet means the maximum lifting force, determined in ideal conditions, that is:

• with the use of low-carbon steel plate acting as a magnetic yoke
• with a thickness of minimum 10 mm
• with a refined outer layer
• with zero air gap
• under perpendicular detachment force
• under standard ambient temperature

What influences lifting capacity in practice

Practical lifting force is determined by elements, 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 was assessed using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under parallel forces the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the load capacity.