UMGZ 42x20x9 [M8] GZ / N38 - magnetic holder external thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their exceptional magnetic power, neodymium magnets offer the following advantages:

• They do not lose their strength approximately 10 years – the decrease of lifting capacity is only ~1% (theoretically),
• They are extremely resistant to demagnetization caused by external magnetic fields,
• Because of the lustrous layer of silver, the component looks visually appealing,
• They have very high magnetic induction on the surface of the magnet,
• With the right combination of materials, they reach excellent thermal stability, enabling operation at or above 230°C (depending on the structure),
• The ability for accurate shaping and adjustment to custom needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
• Important function in cutting-edge sectors – they find application in hard drives, electric motors, clinical machines or even 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 external force, it is suggested to place them in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from damage while also increases its overall robustness,
• High temperatures may significantly reduce the magnetic power of neodymium magnets. Typically, above 80°C, they experience permanent loss in performance (depending on form). 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,
• Due to corrosion risk in humid conditions, it is common to use sealed magnets made of protective material for outdoor use,
• Limited ability to create threads in the magnet – the use of a mechanical support is recommended,
• Possible threat linked to microscopic shards may arise, when consumed by mistake, which is important in the health of young users. Additionally, small elements from these magnets may hinder health screening 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 contributes to it?

The given strength of the magnet represents the optimal strength, calculated under optimal conditions, 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 refined outer layer
• with no separation
• in a perpendicular direction of force
• at room temperature

Impact of factors on magnetic holding capacity in practice

Practical lifting force is determined by elements, listed from the most critical to the less 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.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.