NC NeoCube fi 5 mm kuleczki kolorowe / N38 - neocube

Strengths and weaknesses of NdFeB magnets.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They have stable power, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• Magnets perfectly defend themselves against loss of magnetization caused by external fields,
• The use of an metallic coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• Neodymium magnets achieve maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to flexibility in shaping and the capacity to modify to complex applications,
• Fundamental importance in modern industrial fields – they find application in computer drives, brushless drives, medical equipment, as well as modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in miniature devices

Cons of neodymium magnets and ways of using them

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited ability of creating nuts in the magnet and complex shapes - preferred is a housing - mounting mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small elements of these devices are able to disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what it depends on?

The force parameter is a measurement result executed under standard conditions:

• using a sheet made of mild steel, serving as a circuit closing element
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• under perpendicular force vector (90-degree angle)
• at temperature room level

Determinants of lifting force in real conditions

It is worth knowing that the application force will differ subject to the following factors, starting with the most relevant:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Load vector – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – insufficiently thick steel does not accept the full field, causing part of the flux to be lost into the air.
• Material composition – not every steel attracts identically. Alloy additives worsen the attraction effect.
• Smoothness – full contact is obtained only on polished steel. Rough texture create air cushions, reducing force.
• Temperature influence – high temperature reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed with the use of a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under shearing force the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate decreases the lifting capacity.