MW 12x3 / N38 - cylindrical magnet

Advantages and disadvantages of neodymium magnets.

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

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (according to literature),
• They retain their magnetic properties even under external field action,
• A magnet with a shiny silver surface has better aesthetics,
• Magnetic induction on the surface of the magnet remains strong,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for functioning at temperatures reaching 230°C and above...
• Thanks to flexibility in shaping and the ability to customize to complex applications,
• Significant place in advanced technology sectors – they find application in data components, electric drive systems, medical equipment, and other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which makes them useful in small systems

Problematic aspects of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Limited ability of producing nuts in the magnet and complex shapes - preferred is casing - magnet mounting.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. Furthermore, small elements of these magnets can disrupt the diagnostic process medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Maximum lifting force for a neodymium magnet – what it depends on?

The specified lifting capacity represents the limit force, measured under optimal environment, specifically:

• with the contact of a sheet made of special test steel, ensuring maximum field concentration
• with a thickness minimum 10 mm
• with a surface cleaned and smooth
• with direct contact (without paint)
• for force applied at a right angle (pull-off, not shear)
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

In practice, the actual lifting capacity is determined by a number of factors, ranked from the most important:

• Distance – existence of foreign body (rust, tape, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Steel grade – the best choice is pure iron steel. Cast iron may attract less.
• Surface condition – ground elements ensure maximum contact, which improves force. Uneven metal reduce efficiency.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.