UMS 60x18x8.5x15 / N38 - conical magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain their full power for around 10 years – the loss is just ~1% (based on simulations),
• They remain magnetized despite exposure to magnetic noise,
• Because of the reflective layer of nickel, the component looks aesthetically refined,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• With the right combination of materials, they reach excellent thermal stability, enabling operation at or above 230°C (depending on the design),
• The ability for precise shaping or adjustment to specific needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which enhances their versatility in applications,
• Key role in cutting-edge sectors – they serve a purpose in data storage devices, electric motors, diagnostic apparatus as well as sophisticated instruments,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They are prone to breaking when subjected to a strong impact. If the magnets are exposed to physical collisions, it is suggested to place them in a protective case. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall resistance,
• They lose power at increased temperatures. Most neodymium magnets experience permanent degradation in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• They rust in a damp environment. If exposed to rain, we recommend using encapsulated magnets, such as those made of plastic,
• Using a cover – such as a magnetic holder – is advised due to the limitations in manufacturing complex structures directly in the magnet,
• Possible threat linked to microscopic shards may arise, if ingested accidentally, which is significant in the context of child safety. Moreover, miniature parts from these devices have the potential to complicate medical imaging if inside the body,
• Due to a complex production process, their cost is above average,

Best holding force of the magnet in ideal parameters – what contributes to it?

The given pulling force of the magnet means the maximum force, determined in ideal conditions, that is:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• with no separation
• with vertical force applied
• at room temperature

Magnet lifting force in use – key factors

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

• 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 testing was conducted on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.