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

Advantages as well as disadvantages of neodymium magnets.

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

• They retain magnetic properties for around 10 years – the drop is just ~1% (according to analyses),
• Magnets effectively protect themselves against loss of magnetization caused by foreign field sources,
• Thanks to the smooth finish, the coating of Ni-Cu-Ni, gold, or silver gives an professional appearance,
• The surface of neodymium magnets generates a powerful magnetic field – this is a key feature,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for operation at temperatures approaching 230°C and above...
• Thanks to freedom in forming and the capacity to modify to individual projects,
• Key role in future technologies – they are commonly used in mass storage devices, motor assemblies, precision medical tools, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which makes them useful in small systems

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only secures them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• We suggest casing - magnetic mount, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting force for a neodymium magnet – what contributes to it?

The load parameter shown refers to the limit force, obtained under laboratory conditions, meaning:

• on a block made of mild steel, effectively closing the magnetic field
• whose thickness reaches at least 10 mm
• with an polished contact surface
• under conditions of no distance (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Determinants of lifting force in real conditions

In real-world applications, the real power depends on several key aspects, listed from most significant:

• Gap (betwixt the magnet and the metal), since even a tiny distance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Cast iron may attract less.
• Surface structure – the more even the surface, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Heat – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a small distance {between} the magnet and the plate decreases the load capacity.