MW 6x6 / N38 - cylindrical magnet

Strengths and weaknesses of neodymium magnets.

Apart from their consistent holding force, neodymium magnets have these key benefits:

• They retain magnetic properties for nearly 10 years – the drop is just ~1% (based on simulations),
• They feature excellent resistance to magnetic field loss as a result of external fields,
• In other words, due to the smooth finish of silver, the element looks attractive,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of precise machining as well as adapting to atypical needs,
• Versatile presence in modern technologies – they are utilized in magnetic memories, electric drive systems, diagnostic systems, also other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which enables their usage in compact constructions

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• Neodymium magnets lose 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
• 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 secure oxidation and corrosion.
• We suggest a housing - magnetic mount, due to difficulties in producing threads inside the magnet and complicated forms.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small components of these devices can disrupt the diagnostic process medical after entering the body.
• With large orders the cost of neodymium magnets can be a barrier,

Maximum lifting capacity of the magnet – what it depends on?

Breakaway force was defined for the most favorable conditions, assuming:

• using a base made of high-permeability steel, functioning as a magnetic yoke
• possessing a massiveness of minimum 10 mm to avoid saturation
• characterized by smoothness
• without any clearance between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at ambient temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

It is worth knowing that the application force may be lower influenced by the following factors, in order of importance:

• Air gap (between the magnet and the plate), as even a tiny distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Plate thickness – insufficiently thick sheet does not close the flux, causing part of the power to be lost to the other side.
• Plate material – low-carbon steel attracts best. Alloy admixtures reduce magnetic properties and holding force.
• Surface condition – smooth surfaces ensure maximum contact, which increases force. Rough surfaces weaken the grip.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under shearing force the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate reduces the holding force.