UMP 135x40 [M10+M12] GW F 600 kg / N38 - search holder

Strengths and weaknesses of NdFeB magnets.

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

• Their power is maintained, and after around ten years it decreases only by ~1% (theoretically),
• Magnets perfectly protect themselves against loss of magnetization caused by external fields,
• In other words, due to the metallic layer of nickel, the element becomes visually attractive,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of precise shaping and adapting to individual applications,
• Versatile presence in advanced technology sectors – they serve a role in HDD drives, drive modules, precision medical tools, as well as industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At strong impacts they can break, 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 force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures 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 prevent oxidation as well as corrosion.
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small elements of these devices can complicate diagnosis medical after entering the body.
• With mass production the cost of neodymium magnets can be a barrier,

Maximum lifting capacity of the magnet – what contributes to it?

The load parameter shown concerns the maximum value, recorded under optimal environment, namely:

• with the use of a yoke made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of at least 10 mm to avoid saturation
• with a plane perfectly flat
• under conditions of ideal adhesion (surface-to-surface)
• for force acting at a right angle (in the magnet axis)
• at room temperature

Lifting capacity in real conditions – factors

It is worth knowing that the application force may be lower influenced by the following factors, starting with the most relevant:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Chemical composition of the base – low-carbon steel gives the best results. Higher carbon content lower magnetic properties and holding force.
• Plate texture – ground elements guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
• Operating temperature – 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 conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.