MW 6x2 / N38 - cylindrical magnet

Advantages as well as disadvantages of NdFeB magnets.

Apart from their superior holding force, neodymium magnets have these key benefits:

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (in testing),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• In other words, due to the reflective layer of nickel, the element is aesthetically pleasing,
• Magnets exhibit excellent magnetic induction on the working surface,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures approaching 230°C and above...
• Thanks to freedom in designing and the capacity to modify to specific needs,
• Key role in high-tech industry – they find application in hard drives, electromotive mechanisms, advanced medical instruments, as well as modern systems.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Cons of neodymium magnets and ways of using them

• At strong impacts they can crack, therefore we recommend placing them in special holders. 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 power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated forms.
• Health risk to health – tiny shards of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child safety. Furthermore, tiny parts of these devices are able to complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Highest magnetic holding force – what affects it?

The load parameter shown refers to the maximum value, recorded under laboratory conditions, specifically:

• using a plate made of low-carbon steel, serving as a ideal flux conductor
• with a thickness of at least 10 mm
• with an polished touching surface
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• at standard ambient temperature

Magnet lifting force in use – key factors

It is worth knowing that the application force may be lower influenced by elements below, starting with the most relevant:

• Distance – the presence of any layer (paint, dirt, air) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (typically approx. 20-30% of nominal force).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Surface condition – ground elements ensure maximum contact, which improves force. Rough surfaces weaken the grip.
• Thermal factor – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, however 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 holding force.