UMGGW 88x8.5 [M6] GW / N38 - magnetic holder rubber internal thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from their consistent magnetism, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years, the performance loss is only ~1% (in laboratory conditions),
• They show superior resistance to demagnetization from external magnetic fields,
• Thanks to the glossy finish and nickel coating, they have an visually attractive appearance,
• The outer field strength of the magnet shows remarkable magnetic properties,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to profile),
• Thanks to the freedom in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in diverse shapes and sizes, which expands their usage potential,
• Important function in advanced technical fields – they find application in computer drives, electric drives, diagnostic apparatus and sophisticated instruments,
• Thanks to their power density, small magnets offer high magnetic performance, in miniature format,

Disadvantages of magnetic elements:

• They can break when subjected to a strong impact. If the magnets are exposed to mechanical hits, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage while also enhances its overall resistance,
• High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent weakening in performance (depending on shape). 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,
• Magnets exposed to humidity can oxidize. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing holes directly in the magnet,
• Health risk linked to microscopic shards may arise, especially if swallowed, which is significant in the health of young users. Moreover, tiny components from these magnets have the potential to complicate medical imaging after being swallowed,
• Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications

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

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

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a polished side
• with no separation
• under perpendicular detachment force
• under standard ambient temperature

Lifting capacity in practice – influencing factors

Practical lifting force is determined by factors, by priority:

• Air gap between the magnet and the plate, as 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 plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet and the plate reduces the load capacity.