UMP 75x25 [M10x3] GW F200 PLATINIUM / N52 - search holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They retain their full power for almost ten years – the loss is just ~1% (in theory),
• Their ability to resist magnetic interference from external fields is impressive,
• Thanks to the polished finish and silver coating, they have an visually attractive appearance,
• They have very high magnetic induction on the surface of the magnet,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to form),
• With the option for fine forming and targeted design, these magnets can be produced in numerous shapes and sizes, greatly improving application potential,
• Significant impact in new technology industries – they are utilized in HDDs, rotating machines, medical equipment as well as technologically developed systems,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to shocks, it is suggested to place them in a protective case. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall resistance,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to humidity can degrade. Therefore, for outdoor applications, it's best to use waterproof types made of rubber,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing complex structures directly in the magnet,
• Possible threat related to magnet particles may arise, when consumed by mistake, which is significant in the family environments. Additionally, miniature parts from these assemblies might complicate medical imaging once in the system,
• In cases of tight budgets, neodymium magnet cost may be a barrier,

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

The given lifting capacity of the magnet corresponds to the maximum lifting force, determined in the best circumstances, specifically:

• with the use of low-carbon steel plate serving as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a smooth surface
• in conditions of no clearance
• under perpendicular detachment force
• at room temperature

Key elements affecting lifting force

The lifting capacity of a magnet is influenced by in practice key elements, according to their importance:

• Air gap between the magnet and the plate, since 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 testing was performed on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under shearing force the load capacity is reduced by as much as 5 times. In addition, even a minimal clearance {between} the magnet and the plate reduces the holding force.