AM ucho małe [M8] - magnetic accessories

Strengths and weaknesses of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (in testing),
• They maintain their magnetic properties even under external field action,
• By applying a lustrous coating of nickel, the element presents an aesthetic look,
• Magnetic induction on the surface of the magnet remains maximum,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures approaching 230°C and above...
• Thanks to the potential of accurate molding and adaptation to individualized requirements, neodymium magnets can be modeled in a wide range of forms and dimensions, which expands the range of possible applications,
• Wide application in advanced technology sectors – they find application in data components, electromotive mechanisms, medical devices, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in small systems

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• Due to limitations in producing threads and complex shapes in magnets, we propose using a housing - magnetic holder.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small components of these devices are able to be problematic in diagnostics medical after entering the body.
• With large orders the cost of neodymium magnets is economically unviable,

Maximum lifting force for a neodymium magnet – what affects it?

The load parameter shown represents the peak performance, recorded under optimal environment, namely:

• with the use of a sheet made of special test steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to ensure full flux closure
• with an ideally smooth touching surface
• with total lack of distance (no paint)
• for force applied at a right angle (pull-off, not shear)
• at temperature approx. 20 degrees Celsius

Determinants of lifting force in real conditions

Real force is affected by working environment parameters, mainly (from priority):

• Clearance – the presence of foreign body (paint, dirt, air) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Steel type – low-carbon steel attracts best. Higher carbon content reduce magnetic permeability and holding force.
• Surface structure – the more even the surface, the larger the contact zone and stronger the hold. Roughness creates an air distance.
• Heat – NdFeB sinters have a sensitivity to temperature. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as 75%. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the load capacity.