NC NeoCube 5 mm kwadraty / N38 - neocube

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose strength, 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 among the best,
• The use of a mirror-like nickel surface provides a refined finish,
• They possess significant magnetic force measurable at the magnet’s surface,
• 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 geometry),
• The ability for precise shaping or customization to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which enhances their versatility in applications,
• Significant impact in advanced technical fields – they find application in hard drives, electric drives, diagnostic apparatus along with other advanced devices,
• Thanks to their concentrated strength, small magnets offer high magnetic performance, in miniature format,

Disadvantages of magnetic elements:

• They can break when subjected to a sudden impact. If the magnets are exposed to external force, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage and additionally reinforces its overall strength,
• High temperatures may significantly reduce the magnetic power of neodymium magnets. Typically, above 80°C, they experience permanent deterioration in performance (depending on size). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• They rust in a moist environment. For outdoor use, we recommend using sealed magnets, such as those made of rubber,
• The use of a protective casing or external holder is recommended, since machining multi-axis shapes in neodymium magnets is not feasible,
• Potential hazard linked to microscopic shards may arise, especially if swallowed, which is important in the protection of children. Moreover, small elements from these magnets may disrupt scanning if inside the body,
• In cases of mass production, neodymium magnet cost is a challenge,

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

The given pulling force of the magnet corresponds to the maximum force, measured under optimal conditions, namely:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• in conditions of no clearance
• with vertical force applied
• under standard ambient temperature

Practical lifting capacity: influencing factors

Practical lifting force is dependent on factors, by priority:

• 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 carried out on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under shearing force the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.