BM 550x180x70 [4x M8] - magnetic beam

Pros and cons of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They have unchanged lifting capacity, and over around 10 years their attraction force decreases symbolically – ~1% (in testing),
• They retain their magnetic properties even under strong external field,
• By applying a shiny coating of gold, the element presents an elegant look,
• Magnetic induction on the surface of the magnet remains very high,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Considering the option of flexible forming and adaptation to individualized requirements, neodymium magnets can be produced in a variety of shapes and sizes, which amplifies use scope,
• Fundamental importance in future technologies – they serve a role in mass storage devices, electric drive systems, precision medical tools, also multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Problematic aspects of neodymium magnets and ways of using them

• To avoid cracks under impact, we suggest using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. 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. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in creating threads and complex shapes in magnets, we recommend using cover - magnetic mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child health protection. Additionally, small elements of these products can disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Highest magnetic holding force – what affects it?

Magnet power was determined for ideal contact conditions, taking into account:

• on a base made of mild steel, perfectly concentrating the magnetic field
• whose transverse dimension is min. 10 mm
• with a plane cleaned and smooth
• with zero gap (no paint)
• under vertical force vector (90-degree angle)
• at room temperature

Magnet lifting force in use – key factors

It is worth knowing that the application force will differ depending on 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 dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Metal type – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Plate texture – smooth surfaces ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Thermal environment – temperature increase causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet and the plate reduces the holding force.