BM 750x180x70 [4x M8] - magnetic beam

Pros as well as cons of NdFeB magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain magnetic properties for almost 10 years – the drop is just ~1% (based on simulations),
• Magnets perfectly defend themselves against loss of magnetization caused by external fields,
• The use of an metallic layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• The surface of neodymium magnets generates a intense magnetic field – this is a distinguishing feature,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures reaching 230°C and above...
• Thanks to freedom in forming and the ability to adapt to client solutions,
• Wide application in future technologies – they find application in magnetic memories, motor assemblies, medical devices, also multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which allows their use in compact constructions

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited ability of creating threads in the magnet and complicated forms - preferred is cover - magnetic holder.
• Possible danger related to microscopic parts of magnets can be dangerous, in case of ingestion, which gains importance in the context of child health protection. Furthermore, small elements of these devices can be problematic in diagnostics medical after entering the body.
• With mass production the cost of neodymium magnets is a challenge,

Optimal lifting capacity of a neodymium magnet – what affects it?

The declared magnet strength refers to the limit force, obtained under optimal environment, meaning:

• using a sheet made of mild steel, serving as a magnetic yoke
• whose transverse dimension reaches at least 10 mm
• with an polished contact surface
• without the slightest insulating layer between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• at standard ambient temperature

Key elements affecting lifting force

In real-world applications, the actual lifting capacity results from many variables, presented from most significant:

• Distance (between the magnet and the plate), since even a very small clearance (e.g. 0.5 mm) results in a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Chemical composition of the base – mild steel gives the best results. Alloy admixtures decrease magnetic properties and lifting capacity.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet and the plate decreases the lifting capacity.