UMP 135x40 [M10+M12] GW F600 Lina / N38 - search holder

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from their notable power, neodymium magnets have these key benefits:

• They have constant strength, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• Their ability to resist magnetic interference from external fields is impressive,
• Because of the lustrous layer of silver, the component looks high-end,
• Magnetic induction on the surface of these magnets is very strong,
• Thanks to their high temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• With the option for tailored forming and targeted design, these magnets can be produced in multiple shapes and sizes, greatly improving engineering flexibility,
• Wide application in modern technologies – they find application in data storage devices, electric drives, healthcare devices or even technologically developed systems,
• Thanks to their power density, small magnets offer high magnetic performance, with minimal size,

Disadvantages of NdFeB 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 strengthens its overall robustness,
• Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (influenced by the magnet’s dimensions). 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 corrode. Therefore, for outdoor applications, we advise waterproof types made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the limitations in manufacturing holes directly in the magnet,
• Health risk related to magnet particles may arise, in case of ingestion, which is crucial in the family environments. It should also be noted that miniature parts from these devices can hinder health screening once in the system,
• Due to a complex production process, their cost is above average,

Maximum lifting capacity of the magnet – what contributes to it?

The given strength of the magnet means the optimal strength, assessed in ideal conditions, specifically:

• with the use of low-carbon steel plate acting as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• with zero air gap
• under perpendicular detachment force
• in normal thermal conditions

Determinants of practical lifting force of a magnet

The lifting capacity of a magnet depends on in practice the following factors, according to their importance:

• 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 using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.