UMGB 135x40 [M10+M12] GW F600 +Lina GOBLIN / N38 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They retain their full power for almost ten years – the loss is just ~1% (according to analyses),
• They are highly resistant to demagnetization caused by external magnetic sources,
• Because of the brilliant layer of silver, the component looks high-end,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for custom shaping and adaptation to custom needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
• Significant impact in cutting-edge sectors – they are utilized in hard drives, electric motors, healthcare devices or even technologically developed systems,
• Thanks to their power density, small magnets offer high magnetic performance, while occupying minimal space,

Disadvantages of neodymium magnets:

• They are fragile when subjected to a sudden impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage while also increases its overall resistance,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (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 wet conditions can oxidize. Therefore, for outdoor applications, it's best to use waterproof types made of rubber,
• Limited ability to create complex details in the magnet – the use of a mechanical support is recommended,
• Possible threat from tiny pieces may arise, if ingested accidentally, which is notable in the protection of children. Additionally, small elements from these magnets might complicate medical imaging after being swallowed,
• Due to the price of neodymium, their cost is relatively high,

Maximum lifting capacity of the magnet – what affects it?

The given pulling force of the magnet means the maximum 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 refined outer layer
• with zero air gap
• under perpendicular detachment force
• in normal thermal conditions

Practical aspects of lifting capacity – factors

The lifting capacity of a magnet is determined by in practice key elements, from primary to secondary:

• 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.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.