MW 5x30 / N38 - cylindrical magnet

Advantages as well as disadvantages of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (in laboratory conditions),
• They do not lose their magnetic properties even under close interference source,
• Thanks to the shiny finish, the coating of Ni-Cu-Ni, gold, or silver gives an clean appearance,
• Magnets are characterized by very high magnetic induction on the active area,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Thanks to versatility in forming and the ability to adapt to unusual requirements,
• Significant place in modern technologies – they are used in data components, drive modules, advanced medical instruments, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which makes them useful in small systems

What to avoid - cons of neodymium magnets: application proposals

• To avoid cracks under impact, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its 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 durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating threads and complex forms in magnets, we propose using a housing - magnetic mount.
• Possible danger to health – tiny shards 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 products are able to complicate diagnosis medical in case of swallowing.
• With budget limitations the cost of neodymium magnets can be a barrier,

Highest magnetic holding force – what contributes to it?

Information about lifting capacity is the result of a measurement for optimal configuration, taking into account:

• with the application of a yoke made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension equals approx. 10 mm
• characterized by smoothness
• without any clearance between the magnet and steel
• under vertical application of breakaway force (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

In real-world applications, the real power depends on a number of factors, listed from the most important:

• Distance (between the magnet and the plate), since even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Angle of force application – highest force is available only during perpendicular pulling. The force required to slide of the magnet along the surface is typically several times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – insufficiently thick plate causes magnetic saturation, causing part of the flux to be escaped to the other side.
• Material composition – different alloys attracts identically. Alloy additives worsen the attraction effect.
• Smoothness – full contact is obtained only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Temperature influence – high temperature reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate lowers the load capacity.