UMH 42x9x46 [M6] / N38 - magnetic holder with hook

Advantages and disadvantages of NdFeB magnets.

Apart from their superior magnetic energy, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• They feature excellent resistance to magnetism drop when exposed to external fields,
• In other words, due to the smooth layer of gold, the element is aesthetically pleasing,
• Magnetic induction on the surface of the magnet remains maximum,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• In view of the possibility of precise shaping and adaptation to specialized needs, NdFeB magnets can be manufactured in a wide range of geometric configurations, which increases their versatility,
• Key role in advanced technology sectors – they are commonly used in hard drives, electric motors, advanced medical instruments, also complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets and ways of using them

• At very strong impacts they can crack, therefore we advise 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 durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of producing threads in the magnet and complicated forms - recommended is a housing - magnet mounting.
• Potential hazard related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

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

• using a sheet made of low-carbon steel, functioning as a ideal flux conductor
• with a cross-section of at least 10 mm
• with a plane cleaned and smooth
• with direct contact (no impurities)
• under perpendicular force direction (90-degree angle)
• in neutral thermal conditions

Determinants of lifting force in real conditions

Holding efficiency is affected by working environment parameters, including (from priority):

• Air gap (between the magnet and the plate), since even a tiny distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to paint, corrosion or dirt).
• Direction of force – maximum parameter is obtained only during perpendicular pulling. The force required to slide of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Metal type – different alloys attracts identically. Alloy additives worsen the attraction effect.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Operating temperature – neodymium magnets have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured by applying a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the lifting capacity.