KM HF - 22 kg - magnetic bracket

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their remarkable field intensity, neodymium magnets offer the following advantages:

• Their magnetic field is maintained, and after around ten years, it drops only by ~1% (theoretically),
• Their ability to resist magnetic interference from external fields is notable,
• In other words, due to the metallic nickel coating, the magnet obtains an stylish appearance,
• The outer field strength of the magnet shows elevated magnetic properties,
• Neodymium magnets are known for very high magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• The ability for precise shaping and customization to individual needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
• Significant impact in advanced technical fields – they serve a purpose in data storage devices, electric drives, diagnostic apparatus as well as technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in tiny dimensions, which allows for use in small systems

Disadvantages of neodymium magnets:

• They are fragile when subjected to a strong impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage and strengthens its overall resistance,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a moist environment, especially when used outside, we recommend using encapsulated magnets, such as those made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the difficulty in manufacturing fine shapes directly in the magnet,
• Potential hazard related to magnet particles may arise, if ingested accidentally, which is important in the protection of children. It should also be noted that tiny components from these devices may hinder health screening if inside the body,
• Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications

Optimal lifting capacity of a neodymium magnet – what affects it?

The given lifting capacity of the magnet means the maximum lifting force, determined in ideal conditions, namely:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• of a thickness of at least 10 mm
• with a refined outer layer
• in conditions of no clearance
• under perpendicular detachment force
• under standard ambient temperature

Key elements affecting lifting force

The lifting capacity of a magnet is influenced 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, however under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.