UMGGW 66x8.5 [M8] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their remarkable strength, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after 10 years, the decline in efficiency is only ~1% (based on calculations),
• They protect against demagnetization induced by ambient magnetic fields effectively,
• Thanks to the shiny finish and silver coating, they have an aesthetic appearance,
• They have extremely strong magnetic induction on the surface 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 fine forming and personalized design, these magnets can be produced in multiple shapes and sizes, greatly improving design adaptation,
• Wide application in advanced technical fields – they find application in HDDs, electric drives, clinical machines and other advanced devices,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to breaking when subjected to a strong impact. If the magnets are exposed to shocks, we recommend in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture , and at the same time increases its overall strength,
• High temperatures may significantly reduce the field efficiency of neodymium magnets. Typically, above 80°C, they experience permanent deterioration in performance (depending on size). 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 damp environment. For outdoor use, we recommend using sealed magnets, such as those made of polymer,
• Limited ability to create complex details in the magnet – the use of a magnetic holder is recommended,
• Possible threat due to small fragments may arise, if ingested accidentally, which is crucial in the context of child safety. It should also be noted that miniature parts from these products might complicate medical imaging after being swallowed,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which increases the cost of large-scale applications

Maximum lifting force for a neodymium magnet – what it depends on?

The given strength of the magnet means the optimal strength, calculated in ideal conditions, that is:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• with a thickness of minimum 10 mm
• with a refined outer layer
• in conditions of no clearance
• with vertical force applied
• at room temperature

Magnet lifting force in use – key factors

In practice, the holding capacity of a magnet is conditioned by the following aspects, arranged from the most important to the least relevant:

• Air gap between the magnet and the plate, since 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 conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, whereas under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the load capacity.