BM 650x180x70 [4x M8] - magnetic beam

Strengths as well as weaknesses of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They retain attractive force for almost 10 years – the drop is just ~1% (based on simulations),
• They show high resistance to demagnetization induced by external disturbances,
• Thanks to the shiny finish, the surface of Ni-Cu-Ni, gold-plated, or silver-plated gives an clean appearance,
• Magnetic induction on the top side of the magnet turns out to be very high,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of custom modeling as well as adjusting to atypical applications,
• Huge importance in modern technologies – they are used in magnetic memories, electric drive systems, medical devices, and other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• At strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• 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 as well as 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
• They oxidize in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited possibility of making threads in the magnet and complex shapes - recommended is casing - magnetic holder.
• Health risk to health – tiny shards of magnets pose a threat, if swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these devices are able to complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets can be a barrier,

Magnetic strength at its maximum – what it depends on?

Holding force of 0 kg is a measurement result conducted under specific, ideal conditions:

• on a base made of mild steel, optimally conducting the magnetic flux
• possessing a thickness of minimum 10 mm to avoid saturation
• characterized by smoothness
• with direct contact (without impurities)
• under axial force vector (90-degree angle)
• at standard ambient temperature

Lifting capacity in real conditions – factors

Please note that the working load will differ influenced by the following factors, in order of importance:

• Gap (betwixt the magnet and the metal), since even a microscopic distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material composition – not every steel attracts identically. Alloy additives worsen the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Temperature influence – hot environment weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, however under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.