BM 510x180x70 [4x M8] - magnetic beam

Pros and cons of NdFeB magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They have constant strength, and over more than 10 years their performance decreases symbolically – ~1% (in testing),
• They do not lose their magnetic properties even under external field action,
• In other words, due to the metallic layer of nickel, the element looks attractive,
• Neodymium magnets ensure maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures reaching 230°C and above...
• Possibility of custom forming as well as optimizing to atypical conditions,
• Huge importance in high-tech industry – they serve a role in HDD drives, brushless drives, medical devices, also complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

What to avoid - cons of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a special holder, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• We recommend cover - magnetic holder, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small elements of these devices are able to disrupt the diagnostic process medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The declared magnet strength concerns the peak performance, obtained under ideal test conditions, namely:

• with the use of a yoke made of special test steel, ensuring maximum field concentration
• possessing a massiveness of min. 10 mm to ensure full flux closure
• with an ideally smooth touching surface
• under conditions of ideal adhesion (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• at standard ambient temperature

Practical lifting capacity: influencing factors

During everyday use, the actual lifting capacity is determined by several key aspects, ranked from the most important:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Direction of force – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel gives the best results. Alloy steels decrease magnetic permeability and holding force.
• Surface condition – ground elements ensure maximum contact, which increases force. Rough surfaces reduce efficiency.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.