UMP 67x28 [M8+M10] GW F120 kg / N38 - search holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They retain their attractive force for around ten years – the loss is just ~1% (based on simulations),
• They are extremely resistant to demagnetization caused by external field interference,
• Because of the brilliant layer of gold, the component looks aesthetically refined,
• The outer field strength of the magnet shows remarkable magnetic properties,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to profile),
• With the option for tailored forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving design adaptation,
• Wide application in cutting-edge sectors – they serve a purpose in data storage devices, electric drives, medical equipment and other advanced devices,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They can break when subjected to a powerful 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 cracks while also increases its overall durability,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s form). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a wet environment, especially when used outside, we recommend using waterproof magnets, such as those made of plastic,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is difficult,
• Safety concern related to magnet particles may arise, if ingested accidentally, which is crucial in the health of young users. Additionally, small elements from these products can hinder health screening after being swallowed,
• In cases of large-volume purchasing, neodymium magnet cost may be a barrier,

Detachment force of the magnet in optimal conditions – what contributes to it?

The given holding capacity of the magnet represents the highest holding force, measured under optimal conditions, namely:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• with a thickness of minimum 10 mm
• with a smooth surface
• with no separation
• under perpendicular detachment force
• in normal thermal conditions

What influences lifting capacity in practice

The lifting capacity of a magnet depends on in practice key elements, according to their importance:

• 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.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under parallel forces the holding force is lower. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the holding force.