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

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have constant strength, and over more than 10 years their attraction force decreases symbolically – ~1% (in testing),
• They remain magnetized despite exposure to magnetic surroundings,
• Because of the reflective layer of silver, the component looks aesthetically refined,
• They exhibit extremely high 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,
• With the option for customized forming and personalized design, these magnets can be produced in various shapes and sizes, greatly improving design adaptation,
• Significant impact in advanced technical fields – they are used in data storage devices, rotating machines, healthcare devices or even technologically developed systems,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They can break when subjected to a strong impact. If the magnets are exposed to shocks, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time enhances its overall robustness,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent deterioration in performance (depending on height). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• They rust in a humid environment – during outdoor use, we recommend using moisture-resistant magnets, such as those made of polymer,
• Limited ability to create precision features in the magnet – the use of a magnetic holder is recommended,
• Possible threat related to magnet particles may arise, in case of ingestion, which is notable in the health of young users. Additionally, miniature parts from these magnets may complicate medical imaging when ingested,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Best holding force of the magnet in ideal parameters – what it depends on?

The given pulling force of the magnet corresponds to the maximum force, measured in the best circumstances, specifically:

• with mild steel, serving as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a smooth surface
• in conditions of no clearance
• in a perpendicular direction of force
• in normal thermal conditions

Practical lifting capacity: influencing 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, because 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 measured using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate reduces the load capacity.