MP 25x5x5 / N38 - ring magnet

Advantages and disadvantages of neodymium magnets.

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

• Their strength remains stable, and after approximately 10 years it drops only by ~1% (theoretically),
• They possess excellent resistance to weakening of magnetic properties when exposed to opposing magnetic fields,
• The use of an shiny layer of noble metals (nickel, gold, silver) causes the element to present itself better,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures reaching 230°C and above...
• Thanks to the potential of accurate shaping and adaptation to individualized solutions, magnetic components can be modeled in a variety of shapes and sizes, which amplifies use scope,
• Key role in high-tech industry – they are commonly used in computer drives, electric motors, medical equipment, and multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Characteristics of disadvantages 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.
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in realizing threads and complicated forms in magnets, we propose using cover - magnetic holder.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. It is also worth noting that small elements of these devices are able to complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum magnetic pulling force – what contributes to it?

The force parameter is a measurement result performed under standard conditions:

• with the application of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• with a thickness minimum 10 mm
• with an ideally smooth touching surface
• under conditions of no distance (metal-to-metal)
• during detachment in a direction perpendicular to the plane
• in stable room temperature

Lifting capacity in real conditions – factors

Real force is affected by specific conditions, mainly (from most important):

• Distance (between the magnet and the metal), because even a very small distance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
• Load vector – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is standardly several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of converting into lifting capacity.
• Material type – ideal substrate is high-permeability steel. Cast iron may generate lower lifting capacity.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal environment – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.