MW 6x6 / N38 - cylindrical magnet

Strengths as well as weaknesses of rare earth magnets.

Apart from their notable holding force, neodymium magnets have these key benefits:

• They have stable power, and over more than ten years their attraction force decreases symbolically – ~1% (according to theory),
• They are resistant to demagnetization induced by presence of other magnetic fields,
• By applying a smooth layer of gold, the element presents an proper look,
• Magnetic induction on the working layer of the magnet is very high,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of custom machining and adjusting to concrete applications,
• Fundamental importance in future technologies – they are utilized in data components, brushless drives, advanced medical instruments, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in small systems

Cons of neodymium magnets: weaknesses and usage proposals

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a strong case, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding 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 those in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in realizing nuts and complicated forms in magnets, we recommend using a housing - magnetic mount.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these devices are able to complicate diagnosis medical in case of swallowing.
• With large orders the cost of neodymium magnets is economically unviable,

Magnetic strength at its maximum – what affects it?

The lifting capacity listed is a theoretical maximum value executed under the following configuration:

• with the application of a sheet made of low-carbon steel, ensuring full magnetic saturation
• whose thickness is min. 10 mm
• with an ground touching surface
• with total lack of distance (without impurities)
• during pulling in a direction perpendicular to the plane
• at temperature approx. 20 degrees Celsius

Lifting capacity in real conditions – factors

Effective lifting capacity is influenced by working environment parameters, mainly (from most important):

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin sheet causes magnetic saturation, causing part of the power to be wasted to the other side.
• Material composition – not every steel attracts identically. Alloy additives worsen the attraction effect.
• Surface structure – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under shearing force the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate lowers the load capacity.