FM Ruszt magnetyczny do leja fi 200 jednopoziomowy / N52 - magnetic filter

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They retain their full power for nearly ten years – the loss is just ~1% (in theory),
• They are highly resistant to demagnetization caused by external field interference,
• By applying a bright layer of gold, the element gains a sleek look,
• They have extremely strong magnetic induction on the surface of the magnet,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to profile),
• With the option for tailored forming and precise design, these magnets can be produced in numerous shapes and sizes, greatly improving application potential,
• Significant impact in new technology industries – they serve a purpose in computer drives, electric drives, healthcare devices and high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in compact dimensions, which makes them ideal in compact constructions

Disadvantages of NdFeB magnets:

• They can break when subjected to a heavy impact. If the magnets are exposed to external force, 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 field efficiency of neodymium magnets. Typically, above 80°C, they experience permanent loss 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 moisture can oxidize. Therefore, for outdoor applications, we recommend waterproof types made of non-metallic composites,
• Limited ability to create precision features in the magnet – the use of a external casing is recommended,
• Potential hazard due to small fragments may arise, in case of ingestion, which is significant in the protection of children. Moreover, small elements from these assemblies have the potential to disrupt scanning when ingested,
• In cases of mass production, neodymium magnet cost is a challenge,

Magnetic strength at its maximum – what contributes to it?

The given strength of the magnet represents the optimal strength, assessed in the best circumstances, that is:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• with no separation
• under perpendicular detachment force
• under standard ambient temperature

Magnet lifting force in use – key factors

The lifting capacity of a magnet depends on in practice the following factors, ordered from most important to least significant:

• Air gap between the magnet and the plate, as 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 using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the holding force is lower. Additionally, even a small distance {between} the magnet and the plate lowers the load capacity.