BM 750x180x70 [4x M8] - magnetic beam

Pros and cons of rare earth magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They retain attractive force for almost 10 years – the drop is just ~1% (according to analyses),
• Neodymium magnets are remarkably resistant to loss of magnetic properties caused by external magnetic fields,
• The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• In view of the ability of flexible shaping and adaptation to unique needs, NdFeB magnets can be produced in a variety of forms and dimensions, which expands the range of possible applications,
• Wide application in modern industrial fields – they are commonly used in mass storage devices, drive modules, medical devices, also industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated shapes in magnets, we recommend using a housing - magnetic mount.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, tiny parts of these magnets are able to be problematic in diagnostics medical in case of swallowing.
• With mass production the cost of neodymium magnets is a challenge,

Maximum lifting force for a neodymium magnet – what affects it?

The declared magnet strength represents the peak performance, measured under optimal environment, namely:

• on a base made of mild steel, perfectly concentrating the magnetic field
• whose thickness reaches at least 10 mm
• characterized by even structure
• without the slightest air gap between the magnet and steel
• under axial force direction (90-degree angle)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

Bear in mind that the magnet holding will differ subject to the following factors, in order of importance:

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Material type – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture create air cushions, weakening the magnet.
• Temperature influence – hot environment weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate lowers the holding force.