UMGZ 75x34x18 [M10] GZ / N38 - magnetic holder external thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years, the performance loss is only ~1% (according to literature),
• Their ability to resist magnetic interference from external fields is impressive,
• Because of the reflective layer of silver, the component looks aesthetically refined,
• They have exceptional magnetic induction on the surface of the magnet,
• Thanks to their enhanced temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• With the option for customized forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving engineering flexibility,
• Important function in cutting-edge sectors – they are used in data storage devices, electric motors, medical equipment or even technologically developed systems,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to breaking when subjected to a heavy impact. If the magnets are exposed to shocks, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture and reinforces its overall strength,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible power drop (influenced by the magnet’s structure). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to damp air can corrode. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing holes directly in the magnet,
• Potential hazard from tiny pieces may arise, in case of ingestion, which is crucial in the family environments. It should also be noted that tiny components from these devices might interfere with diagnostics when ingested,
• In cases of mass production, neodymium magnet cost may not be economically viable,

Maximum lifting capacity of the magnet – what it depends on?

The given lifting capacity of the magnet represents the maximum lifting force, calculated in a perfect environment, namely:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a smooth surface
• in conditions of no clearance
• with vertical force applied
• under standard ambient temperature

Lifting capacity in practice – influencing factors

The lifting capacity of a magnet depends on in practice key elements, ordered from most important to least significant:

• 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 was measured with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the holding force.