BM 750x180x70 [4x M8] - magnetic beam

Advantages and disadvantages of neodymium magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They have stable power, and over around ten years their performance decreases symbolically – ~1% (in testing),
• They possess excellent resistance to magnetism drop due to opposing magnetic fields,
• Thanks to the metallic finish, the layer of Ni-Cu-Ni, gold-plated, or silver-plated gives an visually attractive appearance,
• Neodymium magnets achieve maximum magnetic induction on a their surface, which allows for strong attraction,
• 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...
• Thanks to modularity in forming and the capacity to customize to client solutions,
• Versatile presence in modern industrial fields – they find application in HDD drives, electric motors, advanced medical instruments, as well as multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. 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 prevent oxidation and corrosion.
• Limited possibility of creating threads in the magnet and complicated shapes - recommended is cover - mounting mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child safety. Additionally, small components of these products can be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

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

Holding force of 0 kg is a result of laboratory testing performed under specific, ideal conditions:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• with a thickness no less than 10 mm
• characterized by smoothness
• with direct contact (no paint)
• for force applied at a right angle (in the magnet axis)
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

During everyday use, the real power results from many variables, ranked from most significant:

• Clearance – existence of any layer (paint, dirt, air) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Material composition – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Temperature – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a minimal clearance {between} the magnet and the plate lowers the load capacity.