MW 29x10 / N38 - cylindrical magnet

Advantages and disadvantages of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over nearly ten years their performance decreases symbolically – ~1% (in testing),
• Magnets effectively resist against demagnetization caused by foreign field sources,
• In other words, due to the smooth surface of silver, the element becomes visually attractive,
• Magnetic induction on the working part of the magnet is maximum,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Possibility of custom modeling and optimizing to concrete conditions,
• Wide application in high-tech industry – they are commonly used in HDD drives, electric motors, advanced medical instruments, as well as modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At 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 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
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated forms in magnets, we recommend using cover - magnetic holder.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these products can complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

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

Holding force of 16.04 kg is a result of laboratory testing conducted under standard conditions:

• on a plate made of structural steel, optimally conducting the magnetic field
• with a cross-section no less than 10 mm
• with an polished contact surface
• under conditions of no distance (metal-to-metal)
• under vertical force direction (90-degree angle)
• at room temperature

Practical aspects of lifting capacity – factors

During everyday use, the actual holding force is determined by a number of factors, presented from crucial:

• Distance (between the magnet and the plate), as even a microscopic distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux penetrates through instead of generating force.
• Material composition – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
• Plate texture – ground elements ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under perpendicular forces, however under shearing force the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate lowers the load capacity.