MW 7x1.5 / N38 - cylindrical magnet

Pros and cons of NdFeB magnets.

Besides their tremendous pulling force, neodymium magnets offer the following advantages:

• They retain attractive force for nearly 10 years – the loss is just ~1% (in theory),
• They are extremely resistant to demagnetization induced by external field influence,
• By using a shiny layer of nickel, the element has an proper look,
• The surface of neodymium magnets generates a unique magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to versatility in forming and the capacity to customize to specific needs,
• Wide application in modern technologies – they are used in magnetic memories, brushless drives, medical equipment, also other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Cons of neodymium magnets and ways of using them

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets lose their strength 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
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in producing nuts and complicated shapes in magnets, we propose using cover - magnetic mount.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. It is also worth noting that small components of these devices can disrupt the diagnostic process medical when they are in the body.
• Due to complex production process, their price is relatively high,

Maximum holding power of the magnet – what affects it?

Holding force of 0.48 kg is a theoretical maximum value performed under specific, ideal conditions:

• on a base made of structural steel, perfectly concentrating the magnetic flux
• whose thickness is min. 10 mm
• with a plane perfectly flat
• with total lack of distance (without paint)
• under vertical application of breakaway force (90-degree angle)
• in temp. approx. 20°C

Impact of factors on magnetic holding capacity in practice

Holding efficiency is influenced by working environment parameters, mainly (from most important):

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits significantly lower power (typically approx. 20-30% of nominal force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel attracts best. Alloy steels lower magnetic properties and lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Thermal environment – heating the magnet causes a temporary drop of force. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate decreases the holding force.