AM ucho [M8] - magnetic accessories

Advantages and disadvantages of neodymium magnets.

Besides their tremendous strength, neodymium magnets offer the following advantages:

• They retain full power for nearly 10 years – the loss is just ~1% (according to analyses),
• They are resistant to demagnetization induced by external disturbances,
• Thanks to the reflective finish, the plating of Ni-Cu-Ni, gold-plated, or silver-plated gives an modern appearance,
• Magnets exhibit exceptionally strong magnetic induction on the working surface,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Due to the potential of precise shaping and adaptation to custom needs, neodymium magnets can be created in a variety of geometric configurations, which expands the range of possible applications,
• Versatile presence in innovative solutions – they are utilized in magnetic memories, motor assemblies, medical devices, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which makes them useful in miniature devices

Problematic aspects of neodymium magnets: weaknesses and usage proposals

• At strong impacts they can break, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets lose their force 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in realizing threads and complex shapes in magnets, we recommend using a housing - magnetic mechanism.
• Health risk to health – tiny shards of magnets are risky, in case of ingestion, which gains importance in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price is higher than average,

Maximum magnetic pulling force – what contributes to it?

The load parameter shown refers to the limit force, measured under ideal test conditions, specifically:

• with the application of a sheet made of special test steel, ensuring maximum field concentration
• whose transverse dimension reaches at least 10 mm
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction vertical to the plane
• at conditions approx. 20°C

Magnet lifting force in use – key factors

Holding efficiency impacted by working environment parameters, such as (from priority):

• Air gap (between the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) results in a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – catalog parameter refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Base massiveness – insufficiently thick steel does not close the flux, causing part of the flux to be escaped to the other side.
• Steel type – mild steel gives the best results. Higher carbon content lower magnetic properties and lifting capacity.
• Base smoothness – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
• Thermal environment – temperature increase causes a temporary drop of force. Check the thermal limit for a given model.

* Lifting capacity was determined by applying a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under parallel forces the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.