NC NeoCube 5 mm kwadraty / N38 - neocube

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They have constant strength, and over nearly ten years their performance decreases symbolically – ~1% (in testing),
• They show exceptional resistance to demagnetization from external field exposure,
• In other words, due to the metallic silver coating, the magnet obtains an professional appearance,
• The outer field strength of the magnet shows elevated magnetic properties,
• With the right combination of magnetic alloys, they reach increased thermal stability, enabling operation at or above 230°C (depending on the design),
• Thanks to the flexibility in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in diverse shapes and sizes, which increases their usage potential,
• Important function in advanced technical fields – they find application in HDDs, electric drives, diagnostic apparatus as well as sophisticated instruments,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They are prone to breaking when subjected to a sudden impact. If the magnets are exposed to shocks, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage while also strengthens its overall resistance,
• They lose power at elevated temperatures. Most neodymium magnets experience permanent decline in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to moisture can rust. Therefore, for outdoor applications, we suggest waterproof types made of rubber,
• Limited ability to create complex details in the magnet – the use of a external casing is recommended,
• Health risk related to magnet particles may arise, especially if swallowed, which is significant in the protection of children. It should also be noted that tiny components from these products have the potential to disrupt scanning after being swallowed,
• Due to a complex production process, their cost is above average,

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

The given pulling force of the magnet means the maximum force, measured in the best circumstances, that is:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a smooth surface
• in conditions of no clearance
• with vertical force applied
• at room temperature

Determinants of lifting force in real conditions

Practical lifting force is dependent on elements, by priority:

• Air gap between the magnet and the plate, because 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.

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet and the plate decreases the holding force.