HH 16x5.3 [M3] / N38 - through hole magnetic holder

Advantages and disadvantages of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• Neodymium magnets are distinguished by exceptionally resistant to magnetic field loss caused by external field sources,
• The use of an elegant coating of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a maximum 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...
• Thanks to modularity in constructing and the capacity to customize to client solutions,
• Wide application in electronics industry – they are utilized in computer drives, electric drive systems, advanced medical instruments, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in miniature devices

Problematic aspects of neodymium magnets: tips and applications.

• At very strong impacts they can crack, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets decrease their strength 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
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited possibility of producing nuts in the magnet and complicated forms - preferred is a housing - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these products can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what it depends on?

The load parameter shown refers to the peak performance, obtained under ideal test conditions, namely:

• with the application of a sheet made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• with a surface perfectly flat
• with direct contact (without paint)
• for force acting at a right angle (pull-off, not shear)
• at temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Real force impacted by working environment parameters, such as (from most important):

• Clearance – the presence of foreign body (rust, tape, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Direction of force – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy admixtures decrease magnetic permeability and holding force.
• Smoothness – ideal contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under parallel forces the load capacity is reduced by as much as 5 times. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.