BM 550x180x70 [4x M8] - magnetic beam

Pros as well as cons of rare earth magnets.

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

• Their power is maintained, and after approximately ten years it decreases only by ~1% (theoretically),
• Neodymium magnets are exceptionally resistant to magnetic field loss caused by external magnetic fields,
• Thanks to the glossy finish, the surface of Ni-Cu-Ni, gold-plated, or silver-plated gives an visually attractive appearance,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to form),
• Thanks to freedom in constructing and the capacity to adapt to client solutions,
• Significant place in advanced technology sectors – they are utilized in hard drives, electromotive mechanisms, medical devices, also modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a strong case, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of producing nuts in the magnet and complicated forms - recommended is a housing - magnet mounting.
• Health risk resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child health protection. Additionally, tiny parts of these devices are able to complicate diagnosis medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Detachment force of the magnet in optimal conditions – what affects it?

The lifting capacity listed is a result of laboratory testing executed under standard conditions:

• using a sheet made of low-carbon steel, serving as a circuit closing element
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• characterized by smoothness
• without any air gap between the magnet and steel
• under perpendicular force vector (90-degree angle)
• in neutral thermal conditions

Magnet lifting force in use – key factors

In practice, the real power is determined by several key aspects, presented from crucial:

• Air gap (between the magnet and the metal), as even a tiny distance (e.g. 0.5 mm) can cause a reduction in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Angle of force application – maximum parameter is available only during perpendicular pulling. The force required to slide of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – insufficiently thick plate causes magnetic saturation, causing part of the flux to be wasted to the other side.
• Steel grade – the best choice is pure iron steel. Hardened steels may generate lower lifting capacity.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Temperature – temperature increase causes a temporary drop of force. Check the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas 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 reduces the holding force.