JM 15x40 - jajka w pudełku/cena za parę - magnetic eggs

Strengths as well as weaknesses of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They do not lose magnetism, even over around ten years – the drop in strength is only ~1% (based on measurements),
• Neodymium magnets are distinguished by exceptionally resistant to magnetic field loss caused by external interference,
• A magnet with a smooth gold surface has an effective appearance,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• In view of the potential of accurate shaping and adaptation to unique requirements, magnetic components can be modeled in a variety of shapes and sizes, which expands the range of possible applications,
• Wide application in future technologies – they are commonly used in magnetic memories, electric motors, medical equipment, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which enables their usage in compact constructions

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• We recommend cover - magnetic mechanism, due to difficulties in producing threads inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Optimal lifting capacity of a neodymium magnet – what contributes to it?

Magnet power was determined for optimal configuration, taking into account:

• with the application of a sheet made of low-carbon steel, ensuring maximum field concentration
• whose transverse dimension reaches at least 10 mm
• with an ground touching surface
• without any air gap between the magnet and steel
• under vertical force vector (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

During everyday use, the actual lifting capacity is determined by a number of factors, ranked from most significant:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Steel thickness – too thin plate causes magnetic saturation, causing part of the power to be escaped to the other side.
• Chemical composition of the base – low-carbon steel gives the best results. Alloy admixtures reduce magnetic properties and holding force.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal factor – hot environment weakens magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.