MW 29x10 / N38 - cylindrical magnet

Advantages as well as disadvantages of NdFeB magnets.

Apart from their consistent magnetism, neodymium magnets have these key benefits:

• They do not lose magnetism, even over nearly 10 years – the decrease in power is only ~1% (based on measurements),
• They feature excellent resistance to magnetism drop as a result of external fields,
• By applying a lustrous coating of silver, the element acquires an aesthetic look,
• Magnetic induction on the surface of the magnet is maximum,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for action at temperatures reaching 230°C and above...
• Thanks to modularity in constructing and the ability to adapt to specific needs,
• Fundamental importance in high-tech industry – they serve a role in computer drives, electromotive mechanisms, medical equipment, as well as other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power 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
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of producing nuts in the magnet and complex forms - recommended is a housing - magnet mounting.
• Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child health protection. Additionally, tiny parts of these devices can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity represents the limit force, measured under laboratory conditions, namely:

• using a sheet made of mild steel, functioning as a circuit closing element
• with a cross-section no less than 10 mm
• with a plane free of scratches
• under conditions of gap-free contact (metal-to-metal)
• under perpendicular application of breakaway force (90-degree angle)
• at conditions approx. 20°C

Practical aspects of lifting capacity – factors

In practice, the actual lifting capacity is determined by many variables, ranked from most significant:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds much less (often approx. 20-30% of nominal force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material type – the best choice is pure iron steel. Hardened steels may generate lower lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Uneven metal weaken the grip.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.