UMP 75x25 [M10x3] GW F200 GOLD / N42 - search holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after 10 years, the decline in efficiency is only ~1% (in laboratory conditions),
• 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 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,
• The ability for precise shaping or adaptation to individual needs – neodymium magnets can be manufactured in many forms and dimensions, which extends the scope of their use cases,
• Important function in cutting-edge sectors – they are utilized in hard drives, electric drives, medical equipment as well as high-tech tools,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of magnetic elements:

• They may fracture when subjected to a strong impact. If the magnets are exposed to shocks, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time strengthens its overall robustness,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (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 moisture can rust. Therefore, for outdoor applications, we suggest waterproof types made of rubber,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing threads directly in the magnet,
• Safety concern due to small fragments may arise, when consumed by mistake, which is crucial in the protection of children. Moreover, minuscule fragments from these magnets can hinder health screening once in the system,
• Due to expensive raw materials, their cost is relatively high,

Maximum lifting capacity of the magnet – what affects it?

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

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a polished side
• in conditions of no clearance
• in a perpendicular direction of force
• under standard ambient temperature

Lifting capacity in practice – influencing factors

The lifting capacity of a magnet is determined by in practice the following factors, ordered from most important to least significant:

• 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 testing was carried out on a smooth plate of optimal thickness, under a perpendicular pulling force, whereas under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate lowers the holding force.