KM HF - 11,3 kg - magnetic bracket

Advantages as well as disadvantages of rare earth magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• Their power is maintained, and after around ten years it drops only by ~1% (theoretically),
• Magnets perfectly protect themselves against loss of magnetization caused by ambient magnetic noise,
• A magnet with a shiny silver surface has better aesthetics,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to versatility in constructing and the capacity to customize to client solutions,
• Significant place in modern industrial fields – they serve a role in mass storage devices, electric motors, diagnostic systems, as well as technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Due to limitations in producing threads and complex forms in magnets, we propose using casing - magnetic mount.
• Possible danger to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small elements of these magnets can complicate diagnosis medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The lifting capacity listed is a theoretical maximum value executed under specific, ideal conditions:

• with the contact of a yoke made of special test steel, guaranteeing full magnetic saturation
• whose thickness is min. 10 mm
• with an ground contact surface
• without any clearance between the magnet and steel
• under vertical force direction (90-degree angle)
• at temperature approx. 20 degrees Celsius

Magnet lifting force in use – key factors

Effective lifting capacity is influenced by working environment parameters, including (from priority):

• Air gap (betwixt the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) leads to a decrease in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Load vector – highest force is available only during perpendicular pulling. The force required to slide of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Chemical composition of the base – low-carbon steel attracts best. Higher carbon content reduce magnetic permeability and lifting capacity.
• Surface finish – ideal contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Thermal conditions – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.