BM 950x180x70 [4x M8] - magnetic beam

Advantages as well as disadvantages of NdFeB magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They have stable power, and over more than 10 years their attraction force decreases symbolically – ~1% (in testing),
• They retain their magnetic properties even under external field action,
• A magnet with a shiny gold surface is more attractive,
• They feature high magnetic induction at the operating surface, which increases their power,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to modularity in designing and the capacity to customize to specific needs,
• Significant place in advanced technology sectors – they are commonly used in magnetic memories, electric motors, precision medical tools, and modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which enables their usage in miniature devices

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (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 very resistant to heat
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of making threads in the magnet and complex shapes - preferred is a housing - magnet mounting.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which gains importance in the context of child health protection. Furthermore, small elements of these magnets are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

Best holding force of the magnet in ideal parameters – what contributes to it?

The load parameter shown concerns the peak performance, obtained under laboratory conditions, namely:

• using a plate made of high-permeability steel, functioning as a ideal flux conductor
• whose thickness is min. 10 mm
• with a plane cleaned and smooth
• with total lack of distance (no impurities)
• during detachment in a direction perpendicular to the mounting surface
• at temperature room level

Lifting capacity in real conditions – factors

Holding efficiency impacted by working environment parameters, mainly (from priority):

• Distance (betwixt the magnet and the plate), because even a tiny distance (e.g. 0.5 mm) can cause a drastic drop in force by up to 50% (this also applies to paint, rust or debris).
• Load vector – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – mild steel gives the best results. Higher carbon content decrease magnetic permeability and lifting capacity.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture create air cushions, weakening the magnet.
• Temperature – temperature increase results in weakening of force. Check the maximum operating temperature for a given model.

* Lifting capacity was measured with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet and the plate lowers the load capacity.