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

Advantages as well as disadvantages of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They have constant strength, and over nearly ten years their attraction force decreases symbolically – ~1% (according to theory),
• They do not lose their magnetic properties even under strong external field,
• By applying a lustrous coating of nickel, the element presents an elegant look,
• The surface of neodymium magnets generates a powerful magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to flexibility in shaping and the ability to adapt to client solutions,
• Fundamental importance in modern technologies – they are commonly used in computer drives, motor assemblies, precision medical tools, as well as other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength 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
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complex shapes in magnets, we recommend using cover - magnetic mechanism.
• Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. Additionally, small elements of these magnets can complicate diagnosis 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 can limit application in large quantities

Optimal lifting capacity of a neodymium magnet – what affects it?

Holding force of 680 kg is a theoretical maximum value conducted under the following configuration:

• on a base made of structural steel, effectively closing the magnetic field
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an polished contact surface
• with zero gap (without paint)
• under axial force direction (90-degree angle)
• at conditions approx. 20°C

Lifting capacity in real conditions – factors

In practice, the actual holding force results from a number of factors, listed from crucial:

• Air gap (between the magnet and the metal), since even a very small clearance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• 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 attracts best. Alloy steels lower magnetic permeability and holding force.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature influence – hot environment reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the holding force is lower. Additionally, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.