SM 32x425 [2xM8] / N52 - magnetic separator

Pros and cons of NdFeB magnets.

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

• They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (according to theory),
• They retain their magnetic properties even under close interference source,
• In other words, due to the metallic finish of nickel, the element is aesthetically pleasing,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Due to the option of free shaping and adaptation to custom needs, neodymium magnets can be created in a broad palette of shapes and sizes, which amplifies use scope,
• Universal use in modern technologies – they are commonly used in hard drives, electromotive mechanisms, medical equipment, as well as other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we advise placing them in strong housings. 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 weakening 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 very resistant to heat
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We recommend casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complex shapes.
• Potential hazard to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child health protection. Furthermore, small components of these magnets can be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price exceeds standard values,

Highest magnetic holding force – what it depends on?

The lifting capacity listed is a measurement result executed under the following configuration:

• using a plate made of mild steel, serving as a ideal flux conductor
• whose thickness equals approx. 10 mm
• with a surface cleaned and smooth
• with direct contact (no paint)
• under axial application of breakaway force (90-degree angle)
• at temperature room level

Determinants of lifting force in real conditions

Holding efficiency impacted by specific conditions, including (from most important):

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Base massiveness – insufficiently thick plate does not accept the full field, causing part of the flux to be wasted into the air.
• Steel grade – ideal substrate is pure iron steel. Stainless steels may attract less.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal environment – heating the magnet results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, however under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.