UMP 75x24 [M8+M10] GW F 200 kg - search holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their remarkable pulling force, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after ten years, the decline in efficiency is only ~1% (according to literature),
• They remain magnetized despite exposure to strong external fields,
• By applying a shiny layer of silver, the element gains a sleek 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 adaptation to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which amplifies their functionality across industries,
• Important function in new technology industries – they find application in data storage devices, electromechanical systems, diagnostic apparatus or even technologically developed systems,
• Thanks to their efficiency per volume, small magnets offer high magnetic performance, in miniature format,

Disadvantages of NdFeB magnets:

• They are fragile when subjected to a sudden impact. If the magnets are exposed to physical collisions, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time strengthens its overall robustness,
• They lose strength at extreme temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the form 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 suggest waterproof types made of non-metallic composites,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is difficult,
• Potential hazard related to magnet particles may arise, if ingested accidentally, which is important in the family environments. Moreover, miniature parts from these assemblies might interfere with diagnostics when ingested,
• In cases of large-volume purchasing, neodymium magnet cost is a challenge,

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

The given lifting capacity of the magnet corresponds to the maximum lifting force, calculated in the best circumstances, that is:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with no separation
• under perpendicular detachment force
• in normal thermal conditions

Key elements affecting lifting force

The lifting capacity of a magnet depends on in practice key elements, ordered from most important to least significant:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) causes 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 measured by applying a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under parallel forces the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate lowers the holding force.