UMGGZ 43x6 [M6] GZ / N38 - rubber magnetic holder external thread

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their tremendous pulling force, neodymium magnets offer the following advantages:

• Their strength is maintained, and after around ten years, it drops only by ~1% (theoretically),
• They are highly resistant to demagnetization caused by external magnetic fields,
• In other words, due to the shiny silver coating, the magnet obtains an aesthetic appearance,
• They possess strong magnetic force measurable at the magnet’s surface,
• With the right combination of compounds, they reach excellent thermal stability, enabling operation at or above 230°C (depending on the structure),
• The ability for custom shaping and customization to custom needs – neodymium magnets can be manufactured in multiple variants of geometries, which amplifies their functionality across industries,
• Key role in modern technologies – they are used in computer drives, electromechanical systems, healthcare devices along with other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in small dimensions, which makes them ideal in small systems

Disadvantages of NdFeB magnets:

• They can break when subjected to a strong impact. If the magnets are exposed to physical collisions, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from fracture and strengthens its overall robustness,
• High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent loss 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 wet environment – during outdoor use, we recommend using moisture-resistant magnets, such as those made of non-metallic materials,
• Limited ability to create precision features in the magnet – the use of a housing is recommended,
• Safety concern linked to microscopic shards may arise, if ingested accidentally, which is crucial in the protection of children. Moreover, minuscule fragments from these magnets can interfere with diagnostics when ingested,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Optimal lifting capacity of a neodymium magnet – what it depends on?

The given lifting capacity of the magnet corresponds to the maximum lifting force, determined in ideal conditions, specifically:

• with mild steel, used as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a polished side
• in conditions of no clearance
• under perpendicular detachment force
• in normal thermal conditions

Lifting capacity in practice – influencing factors

In practice, the holding capacity of a magnet is affected by these factors, arranged from the most important to the least relevant:

• 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 was measured with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.